Click "Print Lesson" button to use your browser print Student Name: Alethea
Date Printed: Jan 11, 2015
Science 3
Unit 11: The Solar System and Beyond
Lesson 1: The Solar System: Planets and Orbits
Duration: Approx. 60 min.
There are one or more assessments in this lesson. Offline assessments and answer keys can be printed from the materials lists. Online assessments must be printed from the assessment itself within the lesson.
Firefox cannot print Flash images. The on-screen images might print as blank spaces. If you need to print this lesson, try using Internet Explorer so that all the images print.
For the Adult
*cherries (4)
*scissors (2)
*honeydew melon (2)
*pea, green (2)
*glue, children's white (2)
*raspberry, small (2)
*cantaloupe (2)
*apple (4)
*index cards (2)
Investigation: Eat Your Way Through the Solar System
1 day
For this Science activity you will need the following food items:
honeydew melon
cantaloupe
apples - 2
cherries - 2
small raspberry
pea
If these items are expensive to buy or difficult to find due to the season, use substitutes of similar size.
honeydew melon
cantaloupe
apples - 2
cherries - 2
small raspberry
pea
If these items are expensive to buy or difficult to find due to the season, use substitutes of similar size.
Lesson 1: The Solar System: Planets and Orbits
| gravity | |
| The attraction between two bodies due to their mass. Gravity provides the force that keeps us planted firmly on the Earth. |
Investigation: Eat Your Way Through the Solar System
This lesson involves eating or working with food. Check with your doctor, if necessary, to find out whether your student will have any allergic reaction to the food.
This activity is best completed online.
| Can you name the eight planets in our solar system? Take an adventure in outer space as you learn about them. You'll find that the planets are different sizes and distances from the sun. Let's blast off! | ||||||||
| Lesson Overview
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This activity is best completed online.
| The Planets You cannot see our solar system all at once. You see the biggest part, the sun, in the daytime. Other parts are visible at night. Some parts cannot be seen easily. How do we know about our solar system? Learn about the solar system and how scientists have studied it. | |||||||||
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| You already know a lot about the sun, Earth, and moon. The Earth revolves around the sun. It takes one year to go around once. The Earth also rotates on its axis, and it takes one day to go around once. The moon revolves around the Earth. That takes about one month. Finally, the moon rotates on its own axis, as the Earth does. The moon rotates more slowly, rotating once in the same time it takes to revolve around the Earth--one month. But the Earth isn't the only planet revolving around the sun. And our moon isn't the only moon revolving around a planet, either. Other planets revolve around our sun, just as we do, with other moons that revolve around those planets. There are even objects revolving around the sun that aren't planets or moons --things such as comets and asteroids. They are all part of what we call the solar system. | |
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| To start with, how do we know about all this stuff in our solar system? The sun and moon are pretty obvious--you can't miss those. But what about the other planets? Have you ever seen one? Actually, you probably have. On a clear night, the sky is full of little lights. Most of them are stars. They are like our sun, only much, much farther away, which is why they look so small. Every now and then, though, you might see a light that isn't a distant star. It might be a lot brighter than any star. It's a planet, and it's right here in our solar system. How do we know the difference? You have to watch carefully, and for a long time, maybe weeks. If you do that, you'll see that planets move across the sky in more complicated paths than stars do. In fact Mars appears to move backwards at times. Sometimes the planets look brighter or dimmer than at other times. Ancient people spent many nights staring at the sky to figure these things out. | |
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Answer(s):
[1]
Things that are far away look small. If you look at a friend two blocks away, you can't make out the details. Similarly, the far away planets and stars look small and we cannot see details without looking through a telescope or going closer.
| So even long ago people knew there were planets in the sky. But everything up there is so far away--how could they see more? Today we know much more, because we have instruments to help us. Just as a microscope lets you see things too tiny for your eyes to make out, a telescope lets you see things very far away as if they were right next door. Other instruments give us new ways to look deeper into the sky as well. Aside from that, people can now go into space--at least a little way. We know a lot about the moon because we've been there. And being able to fly into space means we can get our instruments outside Earth's air. The air can mess up what we see through telescopes. The Hubble Space Telescope, which is in orbit around the Earth, can get super-clear pictures of far-away things. So far, they are much clearer than any picture taken from Earth. | |
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| So what's in the solar system? Solar means sun, which is at the center of the solar system. The sun is a star. It's actually a pretty average-size one--not too big and not too small. Still, it's by far the biggest object in the solar system. In fact, it contains almost all the solar system's mass. If you were the sun, everything else in the solar system together (the Earth, the moon, all the other planets) would have the mass of less than 10 pennies circling around you. Our solar system has eight planets. Starting from the sun and going out, they are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus (YUR-uh-nuhs), and Neptune. They are all very different in size and in distance from the sun. The biggest is Jupiter. The smallest is Mercury. Earth--where you live--is between them in size. | |
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Answer(s):
[1]
Johannes Kepler (1561-1630) discovered three major principles of planetary motion. These principles describe the shapes, sizes, and timing of the planets' orbits around the sun.
| How big are the other things in the solar system, compared to Earth? The sun is the biggest. One hundred and nine Earths could stretch from one side of the sun to the other. The closest planet to the sun, Mercury, is tiny--not much bigger than our moon. Moving out from the sun, Venus is next, only a little bit smaller than Earth in diameter. Then Earth, which is, well...the size of one Earth. After that comes Mars, with about half Earth's diameter. The outer planets are much larger. Jupiter, the largest, has a diameter about eleven times Earth's. Saturn has about nine and a half times Earth's diameter (not including those rings)--almost as big as Jupiter, although Jupiter's much more massive than Saturn. Uranus has four times Earth's diameter, and Neptune is almost the same--just a bit smaller. | |
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| The planets are so far away from Earth that, even reflecting light from the powerful sun, they look like little dots in our sky. And the farthest ones are so distant that they don't even look like dots--we can't see them with our eyes alone. There is lots and lots of empty space between the planets and between each planet and the sun. So how does the solar system stay together? If the planets are so far away, what keeps them from just floating off? You may already know the answer. You may know that a massive object attracts other objects due to gravity. The sun, at the center of the solar system, is so massive that its gravity exerts the main force that holds on to all the planets, even the way, way-out-there ones, such as Neptune. Gravity keeps us all together. It's what makes the solar system a system. | |
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Answer(s):
[1]
Meteoroids are small, rocky objects less than 100km in diameter.
Asteroids are larger rocky objects, 1,000 km or less in diameter, that stay mostly in the region between Mars and Jupiter.
Comets are icy objects that develop "tails" when their path takes them near the sun.
Asteroids are larger rocky objects, 1,000 km or less in diameter, that stay mostly in the region between Mars and Jupiter.
Comets are icy objects that develop "tails" when their path takes them near the sun.
This activity is best completed online.
SAFETY: This lesson involves eating or working with food. Check with your doctor, if necessary, to find out whether your student will have any allergic reaction to the food.
| Eat Your Way Through the Solar System Can you really eat your way through the solar system? No, but you can use different types of food to help you see the relative sizes of all the planets. Print the Eating Your Way Through the Solar System activity sheet if you have not done so already. Follow the activity instructions to complete this activity. |
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This activity is best completed online.
| May I Have Your Order, Please? It's time to become a "Planet Detective." Use clues to help you place the planets in order of their distance from the sun. Print the Planet Clues activity sheet if you have not done so already. Follow the activity instructions to complete this activity. |
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Lesson Assessment: The Solar System: Planets and Orbits
Print this offline assessment and answer key using the links below. You will need to enter your student's results online later.
Click "Print Lesson" button to use your browser print Student Name: Alethea
Date Printed: Jan 11, 2015
Science 3
Unit 11: The Solar System and Beyond
Lesson 2: The Sun
Duration: Approx. 60 min.
There are one or more assessments in this lesson. Offline assessments and answer keys can be printed from the materials lists. Online assessments must be printed from the assessment itself within the lesson.
Firefox cannot print Flash images. The on-screen images might print as blank spaces. If you need to print this lesson, try using Internet Explorer so that all the images print.
This activity is best completed online.
| When you look up in the sky on a bright sunny day, what do you see? The sun! The sun is by far the biggest thing in the whole solar system. It's also the solar system's major source of energy. You have learned about the sun's relationship with Earth and the moon. Now learn more about the sun itself. | | |||||
| Lesson Overview
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This activity is best completed online.
| The Sun Have you ever been sunburned from staying out in the sun for too long? The energy that caused the burn is only a small sample of just how hot and powerful the sun is. Find out more about this amazing, gigantic star. | |||||||||
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| What's the brightest star you've ever seen? No matter who and where you are, the answer is the same. Can you guess? It's the star of this lesson, the sun--our star. We think of stars as tiny points of light we can see only at night, but the sun is a star seen close up. It's so close that it lights up the whole sky and warms up our days. Still, as stars go, the sun's size is average. Stars can be both smaller and much larger. Even if it’s average-sized for a star, our sun is the Earth's biggest source of energy. It's also so massive that its gravity provides the main force keeping all the planets of the solar system together. It may be average compared to other stars, but when you see the sun coming up on a bright morning in spring, you know that the closest star to Earth is also the one that matters most to you. Are you ready to learn more about our sun? | |
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| It's hard to imagine how hot the sun is. If someone told you the sun's surface temperature is 6,000 degrees Celsius, would you believe it? It’s true. Of course, that's how hot it would be if you could measure its surface. Inside the sun, if you could somehow go there with a super-strong thermometer, is more like 15 million degrees Celsius. Now that's hot! Imagining 15 million degrees is almost as hard as imagining how big the sun is. Picture the entire Earth and everything on it. Would all of that fit inside the sun? Yes, it would. So would two Earths, and three, and four. In fact, the sun is so big that 1,300,000 Earths would fit inside it. It would take 109 Earths lined up just to stretch from one side of the sun to the other. Now that's big! | |
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| So what is that big, hot sun made of? Even though it's really massive, the sun is mostly made of hydrogen and helium, the two lightest elements. If they're so light, how can the sun be so massive? By having tons and tons of hydrogen and helium, all packed very tightly in the center. There's also a tiny amount of other elements, including oxygen and carbon. | |
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| The sun's center is called the core. There, the molecules are under a lot of pressure. How much? How does 340 billion times the air pressure on Earth sound? That's enough to crunch hydrogen atoms together and make them into helium--kind of like taking two little snowballs and forcing them together into one. When hydrogen atoms get smooshed into helium, a process called fusion, they release a lot of energy. It's all that crunching and smooshing of hydrogen that keeps the sun glowing. After that energy made by fusion of hydrogen is released, it moves toward the sun's surface, through more layers. When it gets to the surface, it shines out into space. The photosphere is the outside part of the sun we see shining so brightly in the sky. | |
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| Around the whole thing is the corona (kuh-ROH-nuh). If you drew a cartoon of the sun as a circle with flames all around it, the corona would be those flames. You can see it well when there's an eclipse, because the moon blocks everything else. But when the moon isn't in the way, the photosphere, much brighter than the corona, is the more obvious layer. That's why you see the photosphere as the surface of the sun. But don't try to look at the sun directly, even during an eclipse. The sun's tremendous energy is dangerous to your eyes. | |
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Answer(s):
[1]
In 1903, Bernard Lyot found a way to look at the corona even without an actual eclipse. His coronagraph makes an artifical exclipse by blocking out the light from everything but the corona.
| From here on Earth the sun seems always about the same. Cloudy days come and go, but the sun is always the sun, shining away as usual. Actually, though, that's not exactly right. A lot of changes happen in the sun, even if we don't notice them. Scientists who study the sun with many different instruments find that it has a "stormy" surface. Not thunder and lightning, but gigantic flares of energy shoot out of the sun from time to time. Such explosions send out X-rays and radio waves that can cause trouble for radio communication here on Earth. Still, even if the sun is stormy, it's reliable. Scientists think it has been around for billions of years and will be around for billions more. As long as you or anyone close to you is here to enjoy it, you can expect the sun to be up in the sky--bright, warm, and sending us energy for life. | |
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This activity is best completed online.
| My Solar System Book In the next few lessons you will be creating a book about the entire solar system. Begin your book by drawing the sun, labeling the layers and writing down other important facts you have learned about it. Print the My Solar System Book activity sheet if you have not done so already. Follow the activity instructions to complete this activity. |
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Lesson Assessment: The Sun
Print this offline assessment and answer key using the links below. You will need to enter your student's results online later.
Click "Print Lesson" button to use your browser print Student Name: Alethea
Date Printed: Jan 11, 2015
Science 3
Unit 11: The Solar System and Beyond
Lesson 3: The Inner Planets
Duration: Approx. 60 min.
There are one or more assessments in this lesson. Offline assessments and answer keys can be printed from the materials lists. Online assessments must be printed from the assessment itself within the lesson.
Firefox cannot print Flash images. The on-screen images might print as blank spaces. If you need to print this lesson, try using Internet Explorer so that all the images print.
For the Adult
*tape, clear
*scissors
*toilet paper - rolls (3)
Investigation: My Solar System Book, Part 2
1 day
Have on hand the pages about the sun that your student created in the previous lesson, The Sun. Also, gather the pages of My Solar System Book from earlier lessons in this unit.
Investigation: Make a Model of the Solar System
1 day
For today's lesson you will need the pictures of the planets on index cards, which you used in the first lesson of the unit.
Lesson 3: The Inner Planets
| terrestrial | |
| Earth-like, made mainly of rock and metal, with a solid surface. The terrestrial surface of the planet made it easy for the astronauts to walk there. |
This activity is best completed online.
| You have learned that eight planets orbit the sun. The four planets closest to the sun are similar in many ways, but they also have big differences. Begin your planetary journey by visiting these inner planets to learn what they're like. | | |||||||
| Lesson Overview
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This activity is best completed online.
| The Inner Planets The inner planets are the four planets closest to the sun. Find out what Mercury, Venus, Earth, and Mars have in common, what makes them so different from most of the other planets, and how they differ from one another. | |||||||||
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| You've learned about the enormous size of the sun and the huge amount of energy it releases. You have also learned a little about the planets. The four planets closest to the sun are Mercury, Venus, Earth, and Mars. They are called the inner planets because they are closest to the sun. They have some other things in common that are different from the giant and gaseous outer planets Jupiter, Saturn, Uranus and Neptune. The inner planets are all terrestrial, meaning that they are made mainly of rock and metal. They are solid, not gaseous. They rotate fairly slowly, and have no rings and few natural satellites, or moons. They are the size of the Earth or smaller, less than 13,000 km in diameter. | |
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Answer(s):
[1]
One factor that helps knowledge advance is improvements in tools and methods. Before Galileo built a telescope, people could observe other planets with only their eyes. Only five planets were bright enough to be seen.
| Mercury is the planet closest to the sun. Viewed from Earth, it goes through phases as it moves, like the moon. It's like our moon in many other ways, too. It's the smallest planet, with a diameter only 1 1/2 times the moon's. Being small with little gravity and very hot, Mercury doesn't have an atmosphere. That means there is no air for weather, and craters stay for a long time. | |
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Answer(s):
[1]
The space probe Mariner 10 flew by Mercury three times in 1974 and 1975. Its closest point brought it within about 320 km. (200 mi.) of the planet. It brought back to Earth the first close-up pictures of Mercury and information about its atmosphere.
| Mercury's orbit around the sun is far from circular. Its distance from the sun can be from 46 million km. to 70 million km. Being so near the sun, it's hot there during the day. Temperatures can rise to 467°C (about 870°F)--much hotter than your oven! With no atmosphere to keep heat in, at night it can be -173°C (-280°F)--much colder than a freezer. Also, nights can be long, a whole Mercury year in some places--88 Earth days! Heat absorbed during the day has plenty of time to leave. | |
| Venus is the planet second-closest to the sun. In 1610 Galileo, discovered that, viewed from Earth, Venus has phases just like the moon. This discovery provided evidence for Copernicus's argument that the sun, not the Earth, is the center of the solar system. | |
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Answer(s):
[1]
Two spacecrafts, Mariner 2 (1962) and Mariner 5 (1967), passed within 34,800 km (21,600 mi) and 3,990 km (2,480 mi) of Venus, respectively. They measured its temperature and atmosphere. In the 1970s and 1980s, Soviet spacecrafts actually landed there and sent back information about the atmosphere and the surface.
| Venus is in some ways very similar to the Earth. It has almost the same diameter. Its surface is made of similar material--it's dry and rocky, with mountains and active volcanoes. But it's very different in some ways. There are no oceans and, in fact, no water. Temperatures are hot enough to melt lead. And Venus has a very dense atmosphere that keeps the sun's heat energy in. The atmosphere is almost all carbon dioxide, and its pressure is 90 times the air pressure on Earth! High above the surface are fast-moving clouds made of sulfuric acid, not water. Down near the surface, the winds are slow. | |
| Imagine visiting Earth. Well, you don't have to, because you live here. But imagine visiting here from somewhere else, so that everything you see on Earth is new to you. Your first thought might be: It sure has lots of water! It's mostly seawater, which covers 71 percent--nearly three-quarters--of the planet. It's the only planet known to have liquid water. Its temperature averages about 20°C--a good temperature for liquid water, not near the freezing or boiling points. | |
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| Earth has mountains, plains, valleys, rivers, streams, and lakes. The atmosphere is mostly nitrogen, with a lot of oxygen, and smaller amounts of other substances. The tilt of the axis of rotation of the Earth causes seasons of warm and cold weather, even though its orbit around the sun is almost circular. And don't forget life. Everywhere there's green plants and weird animals! The Earth is a living planet! | |
| Years ago, people thought that there might be life on Mars, too. Recent visits to Mars show us that no obvious life is there now. But Mars has water--not liquid, but frozen, just under the surface. Temperatures are mostly like a very cold freezer's. Mars is about 1 1/2 times as far from the sun as Earth is, and has about half the diameter. Its axis is tilted like Earth's, by about the same amount, so Mars has seasons. Days are about the same length as Earth days, but years are almost twice as long as Earth's. | |
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Answer(s):
[1]
Between 1965 and 1972, four Mariner spacecraft photographed the surface of Mars and analyzed its atmosphere. More recent craft have landed on Mars, sending back photos and analyzing rocks.
| Polar ice caps grow and shrink with changing seasons. Huge canyons indicate that lots of liquid water was once on Mars. As on Venus, the atmosphere is mostly carbon dioxide. But unlike Venus, the atmosphere on Mars is very light--much less than on Earth. Still, there's enough atmosphere for dust storms, which are common on Mars. | |
| Mercury - Venus - Earth - Mars. Those are the four inner planets. Venus and Earth are similar in size and made of similar matter, but Venus is much hotter and has a much denser atmosphere. Mercury, closest to the sun, is very much like the moon in some ways: it has no atmosphere and is very hot during its very long day, and very cold during its very long night. Mars is half the size of the Earth, and farther from the sun. It's cold, has days about the length of Earth days, seasons, and has water in the form of ice. And Earth has life! All these inner planets are very different from the four gas-giant outer planets that we'll learn about next. The outer planets are far out! | |
This activity is best completed online.
| My Solar System Book, Part 2 The four inner planets have characteristics in common, and each has characteristics that make it unique. Think about both types of characteristics as you add the inner planets to your solar system book. Print the My Solar System Book activity sheet if you have not done so already. Follow the activity instructions to complete this activity. |
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This activity is best completed online.
| Make a Model of the Solar System Just how far are the inner planets from the sun? A roll of toilet paper can help you understand! Print the Planet Distances Chart activity sheet if you have not done so already. Follow the activity instructions to complete this activity |
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Lesson Assessment: The Inner Planets
This assessment is best completed online, where it will be automatically scored by the computer. If you would like to print it, do so from the assessment itself within the lesson.
Click "Print Lesson" button to use your browser print Student Name: Alethea
Date Printed: Jan 11, 2015
Science 3
Unit 11: The Solar System and Beyond
Lesson 4: The Outer Planets
Duration: Approx. 60 min.
There are one or more assessments in this lesson. Offline assessments and answer keys can be printed from the materials lists. Online assessments must be printed from the assessment itself within the lesson.
Firefox cannot print Flash images. The on-screen images might print as blank spaces. If you need to print this lesson, try using Internet Explorer so that all the images print.
For the Adult
*pencils, colored 12
*toilet paper - rolls (2)
*scissors
*stapler
Investigation: My Solar System Book, Part 3
1 day
Have on hand the pages about the sun and the inner planets that your student created in the previous lessons. Also, gather the pages of My Solar System Book from the previous lessons.
Investigation: Make a Model of the Solar System, Part 2
1 day
Have on hand the toilet-paper strips representing the distances from the sun of the inner planets. For today's lesson you will need the planets cards you used in the first lesson of the unit. Also, gather the previous work of the toilet-paper model.
This activity is best completed online.
| Continue your planet journey as you travel farther away from the sun to the outer planets. See what makes these planets different from the inner planets, and how they compare to one another. | | |||||||
| Lesson Overview
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This activity is best completed online.
| Far Out! Are you ready to learn about the giants of the solar system? You will find that the four outer planets are very different from the inner planets. | |||||||||
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| In the rocket of your imagination you've visited the four inner planets: Mercury, Venus, Earth, and Mars. You learned about their sizes, their distance from the sun, and their day lengths. Now let's go deeper into space. The four outer planets are much larger than the inner planets. What's also different is that their surfaces are not solid. They're made of gas, like huge, dense clouds. That's why Saturn, Jupiter, Uranus, and Neptune are called gas giants. Their moons are solid enough, though, and they all have plenty of moons, and rings. | |
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Answer(s):
[1]
Uranus and Neptune are so far out and hard to see, that no one knew they were there until telescopes were invented. But if conditions are just right it's sometimes possbile to see Uranus.
| Other objects, smaller than planets, also orbit the sun. Many are in big collections called belts. One of these belts is between Mars and Jupiter. The other is beyond Neptune. But the real show is the giants of the solar system. Are you ready to play with the big kids--the outer planets? | |
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| As your rocket goes out past Mars, the first gas giant you reach is also the doozy of them all. Jupiter is the biggest. It's over twice as massive as all the others combined. In fact, it's like a little star, except it's not putting out light. But it does put out heat. It would have become a star if it were a little bigger. Jupiter's atmosphere is mainly hydrogen and helium, which stars are made of. | |
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Answer(s):
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An asteroid belt exists between the inner planets and outer planets, specifically between the orbits of Mars and Jupiter. Asteroids have an irregular shape and are smaller than planets. The largest is about 1000 km. across. They are referred to as planetoids. The asteroid belt is between the inner planets and the outer ones.
| Like a star, Jupiter has no solid surface. Instead, it is made of thick gases, becoming a dense, hot liquid toward the center. The very center is rocky, possibly molten (melted). It even has its own "mini-solar system"--67 known moons and more being discovered on a regular basis. Many are very small--less than 4 km across--but four are large, and one is larger than Mercury. Jupiter is like an almost-star surrounded by almost-planets. Jupiter rotates in 10 hours. It takes about 12 Earth years to orbit the sun. It has rings of small particles and dust. | |
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| Next you come to Saturn, with the most spectacular, biggest rings. Saturn's huge, too. It's almost as big as Jupiter, but has only 1/3 Jupiter's mass. That makes it the least dense of the gas giants. Like Jupiter, Saturn is made mostly of hydrogen, and has no surface you could land on. It has clouds of ammonia on top and high-pressure liquid inside, with a rocky core. Saturn's cold, too. In the atmosphere the temperature gets down to -190°C. Things get hotter as you move in deeper. | |
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Answer(s):
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Passing near Saturn, Pioneer 11 (in 1979) and Voyagers 1 and 2 (in 1980 and 1981) have provided much useful information about the planet. In 2001, Mars Odyssey was put into orbit around Saturn to help us learn even more.
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If your student is confused by the idea of a planet not having a surface, explain that Saturn only has a surface in the same sense that a cloud in the sky does. It ends at a certain place, but if you tried to land a spaceship on it you would sail right through.
| Saturn has at least 30 moons. The biggest is bigger than Mercury, like a planet itself. Best of all, though, Saturn has those terrific rings. Jupiter, Uranus, and Neptune have rings, too, but Saturn's are the most visible and well known. If you could steer your rocket close you'd find the rings are made of ice chunks. Some are beach-ball size, some smaller. The rings only look solid from far away. | |
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| Next comes Uranus. Like the others, it's made of gas, with liquid and a rocky core down deep. It's also mostly hydrogen and helium. Uranus has rings, too--11 of them--and 21 known moons. The strangest thing is its axis of rotation. It's tipped entirely over, rotating ''on its side.'' That means it has dramatic seasons. Each season is about 21 Earth years. Imagine it near the poles. In one season, the sun does not set for many Earth years. Next season it rises and sets every 17 hours! Then it doesn't rise again for years. Even so, Uranus is so far from the sun that it's always very cold. | |
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Answer(s):
[1]
Voyager 2 flew by Uranus in 1986, and gathered information about the planet's rotation and structure.
[2]
Your student can get a sense of Uranus's rotation ''on its side'' by lifting a globe up by its axis, holding the axis horizontally and having someone else spin the globe. (You could use an orange with an axis, with a pin for location on it, as for the lesson on The Seasons.) You can demonstrate the times between sunrise and sunset in different seasons and on different parts of Uranus by moving it around a central object (bare lightbulb) representing the sun, keeping the globe in the same orientation with respect to the room.
A pea 5 mm in diameter held 10 meters away would have the visual diameter of the sun from Uranus. It still would be very bright, even if just 1/400 the brightness of the sun we know. It would still have about 1100 times the brightness of our full moon.
A pea 5 mm in diameter held 10 meters away would have the visual diameter of the sun from Uranus. It still would be very bright, even if just 1/400 the brightness of the sun we know. It would still have about 1100 times the brightness of our full moon.
| We're getting really far out now. In your imagination, stop your rocket and take a look back. Since Uranus is 20 times farther from the sun than Earth, the sun will only appear 1/20 as big across and 1/400 as bright. Can you imagine the sun looking like a bright pea in the sky? | |
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Answer(s):
[1]
Your student can get a sense of Uranus's rotation ''on its side'' by lifting a globe up by its axis, holding the axis horizontally and having someone else spin the globe. (You could use an orange with an axis, with a pin for location on it, as for the lesson on The Seasons.) You can demonstrate the times between sunrise and sunset in different seasons and on different parts of Uranus by moving it around a central object (bare lightbulb) representing the sun, keeping the globe in the same orientation with respect to the room.
A pea 5 mm in diameter held 10 meters away would have the visual diameter of the sun from Uranus. It still would be very bright, even if just 1/400 the brightness of the sun we know. It would still have about 1100 times the brightness of our full moon.
A pea 5 mm in diameter held 10 meters away would have the visual diameter of the sun from Uranus. It still would be very bright, even if just 1/400 the brightness of the sun we know. It would still have about 1100 times the brightness of our full moon.
| Neptune is the gas giant that is farthest from the sun. It's so far out it wasn't discovered until 1846. You can't see it without a telescope. Neptune takes almost 165 Earth years to orbit the sun, so it has only had one complete Neptune year since its discovery. Neptune is very cold but it releases its own heat, which warms it up a little. Neptune is the stormiest planet with the fastest winds, which blow at thousands of kilometers per hour. | |
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Answer(s):
[1]
Voyager 2 in 1989 discovered six of Neptune's thirteen known moons.
| Looking out your rocket's window, the first thing you notice about Neptune is its beauty! It has a rich, deep blue color, like a drop of ocean water. That's the atmosphere. It's mostly hydrogen and helium, but some methane absorbs red light, giving it that wonderful blue color. Neptune has rings, thirteen known moons, and seasons due to a tilted axis. Well, the seasons are 41 years long, 1/4 its year. That's a long winter, but it's always cold. | |
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| Wait a minute! What about Pluto? Isn't that a planet? From the first time Pluto was found, some scientists thought tiny Pluto shouldn't be called a planet. It was always an oddball. For example, it's smaller than our moon, even though it has its own moon, Charon (KAIR-uhn), about half the diameter of Pluto itself. Also, its orbit is much less circular than those of the other planets. It swings in closer to the sun and then farther out again. After years of debate, scientists decided in 2006 that Pluto was not a true planet; instead Pluto is considered a "dwarf planet." | |
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Answer(s):
[1]
In a region beyond Neptune, comets, asteroids, and other objects orbit the sun. In 2002 a planet-like object, with about half Pluto's diameter, was found there and named Quaoar. Scientists debate whether it should be called a planet, as well as whether Pluto should be. Several others like it have also been found.
[2]
The sun from Earth is about the visual size of a centimeter held a meter away, like a penny (about 2 cm) held 2 meters away (try it), or a 5 mm diameter pea held ½ meter away. So being 1/50 the size, like from Pluto, means it would be like 1/5 mm held a meter away, less than half a mm held 2 meters away, or a 5 mm diameter pea held 25 meters away. These are very small dots. Nevertheless, it would still shine with about 180 times the brightness of our full moon from just this tiny point.
| Whatever you call it, land on Pluto and have a final look back. The sun looks 1/50 its diameter from Earth, 1/2500 as bright. It's brighter than our full moon, but tiny. Does that make you feel lonely for home--or does it make you want to travel more, to see all those other suns? | |
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This activity is best completed online.
| My Solar System Book, Part 3 Complete your My Solar System Book by adding pictures and descriptions of the five outer planets. Print the My Solar System Book activity sheet if you have not done so already. Follow the activity instructions to complete this activity. |
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This activity is best completed online.
| Make a Model of the Solar System, Part 2 Add the outer planets to your toilet-paper model to show how far these planets are from the sun compared to each other and compared to the inner planets. Print the Planet Distances Chart activity sheet if you have not done so already. Follow the activity instructions to complete this activity. |
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Lesson Assessment: The Outer Planets
This assessment is best completed online, where it will be automatically scored by the computer. If you would like to print it, do so from the assessment itself within the lesson.
Click "Print Lesson" button to use your browser print Student Name: Alethea
Date Printed: Jan 11, 2015
Science 3
Unit 11: The Solar System and Beyond
Lesson 5: Stars of the Night Sky
Duration: Approx. 60 min.
There are one or more assessments in this lesson. Offline assessments and answer keys can be printed from the materials lists. Online assessments must be printed from the assessment itself within the lesson.
Firefox cannot print Flash images. The on-screen images might print as blank spaces. If you need to print this lesson, try using Internet Explorer so that all the images print.
For the Adult
*paper, 8 1/2 x 11"
*scissors
*light bulb, 40 watt
*ruler
*tape, clear
*light bulb, 100 watt
*lamp - table (no shade)
*book
Investigation: Star Bright
1 day
Have on hand a 40-watt bulb and a 100-watt bulb for this lesson.
Investigation: Star Bright
The light bulb will become hot after a short amount of use. Allow time for it to cool before taking it out of the lamp.
This activity is best completed online.
| When you look up on a clear night, the sky seems to sparkle with millions of tiny white lights. Almost all these white lights are stars up in space. The stars may look tiny, but they are actually huge. Explore stars and learn how something so big can look so small. | | |||||
| Lesson Overview
|
This activity is best completed online.
| Stars in Space Some stars may appear larger or brighter than others, but are they really? Explore the night sky and find out! | |||||||||
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| Have you ever looked out the rear window of a car as you drove away from a building? You look back and see the building getting smaller and smaller. It isn't really shrinking, but it looks that way because the distance between you and the building is growing. Now imagine zooming away from the sun in a rocket. The farther you go, the smaller the sun looks. As you fly past Jupiter, the sun gets dimmer and dimmer in your rearview mirror. By the time you stop on Pluto, you are 50 times farther away from the sun than you were on Earth. The sun appears only 1/50 as big as from Earth. It's also 1/2500 as bright. Click to compare an Earth scene with what it might look like at Pluto's farthest distance from the sun. | |
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Answer(s):
[1]
Even though the sun seen from Pluto would have 1/2500 its brightness from Earth, and 1/50 the diameter, it would still be bright. It would be about 180 times the brightness of our full moon. Even the nearest star other than the sun is very much farther away from Pluto than the sun ever is, and would not look nearly as bright as the sun.
| Just as the sun's brightness would depend on its distance, the brightness of all stars depends on how far away they are. That means if two stars are similar, the dimmer one must be farther away. Brightness is affected by things other than distance, though. You could have two stars at the same distance and still have one appear brighter than the other. How? | |
| The brighter star puts out more light energy. It could do that two ways. It could be the same size and brighter. Or it could put out the same energy from any part, but be much bigger. A stadium full of shouting people puts out more energy than one shouting person. Either way, the star giving off more energy will be seen as brighter. If you understand the stadium you can also see that two stars which are close enough together to seem like one will appear brighter than either star alone. Their light adds to make the pair twice as bright. Of course, then three stars together will be even brighter, and ten brighter still. You can see that many stars close together in the sky look brighter than single ones or smaller groups. | |
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Answer(s):
[1]
Galaxies -- large groups of stars --can have billions of members. our own galazy is estimated to have 100 billion stars. In very far-away galaxies, individual stars may not be visible because of their great distance, but we can still see their light combined as a bright galaxy.
| The first thing you notice about a star is how bright it is. So scientists describe stars by brightness. The system was invented by Hipparchus (huh-PAHR-kuhs), a Greek astronomer. The brightest stars were first magnitude stars, the next brightest second magnitude, and so on. The dimmest ones he could see were sixth magnitude. As scientists developed ways to measure light more exactly, they extended the system to cover stars dimmer than Hipparchus could see and brighter objects than he considered. | |
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Answer(s):
[1]
Brightness, by itself, doesn't tell how far away a star is. A dim star near you might have the same brightness as a bright star far away. That's because, thanks to its distance, the bright one can look smaller and dimmer.
[2]
If your student has trouble understanding magnitude numbers less than zero, point out that they are like temperatures. Very low temperatures are less than zero degrees. Likewise, very bright stars or other objects have magnitudes less than zero. Our sun has magnitude -26.7, and the full moon has magnitude -12.6. At its brightest, Venus has magnitude -4.4.
| Now a visual magnitude number can be between whole numbers, and can be less than 1, even less than zero. It tells you exactly how bright a star looks. Each difference of 1 in magnitude means a multiple of 2½ in brightness. A magnitude 1 star is 2½ times as bright as a magnitude 2 star. A magnitude 2 star is 2½ times as bright as a magnitude 3 star, and so on. | |
|
Answer(s):
[1]
If your student has trouble understanding magnitude numbers less than zero, point out that they are like temperatures. Very low temperatures are less than zero degrees. Likewise, very bright stars or other objects have magnitudes less than zero. Our sun has magnitude -26.7, and the full moon has magnitude -12.6. At its brightest, Venus has magnitude -4.4.
| Our eyes need light to see. The same is true of a camera--you can't take a picture inside a closed dark closet. The dimmer a star is, the harder it is to see, for us or for our tools. Telescopes allow us to see things too dim for our eyes alone. They gather light from a faint star and focus it in one place. It's like funneling more light to the small pupil of your eye. This lets us see things that would otherwise be too dim to make out. | |
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Answer(s):
[1]
Scientists have extended the range of magnitudes beyond 1 through 6. Now we can describe very dim things we can only see with our senstive instruments, as well as very bright things, such as the sun. magnitudes go from -26.7 (the sun) to +30 (the dimmist things we can see with the Hubble Space Telescope). The +30 refers to something 4 billion times fainter than our eyes can make out.
| Telescopes also can make images bigger, which allows us to see details we would not otherwise see, such as on planets or in groups of stars. Photography and other kinds of equipment also help us see light that would be too dim for just our eyes. These inventions greatly increase the number of stars we can see and the details we can learn about them. To direct and focus light, a refracting telescope uses lenses and a reflecting telescope uses mirrors. | |
| So we can describe a star using its magnitude. A lower number means it's brighter. How bright a star appears depends both on how far away it is and how much light it's putting out. It also depends on whether something between the star and us makes it look dimmer. It's harder to see a car's headlights on a foggy night, because the fog is between you and the light. On a hazy day our star, the sun, does not look as bright as on a clear day. | |
| Scientists have several ways to figure out how far away a star is. They may also be able to tell how much of its light is absorbed or reflected by other stuff before it gets here. With that information, they can then use the star's apparent brightness to figure out how much energy it's putting out. That allows scientists to understand what the stars themselves are like, not just how they look from here. | |
| As you get older, you change in lots of ways. Stars get older, too, and as they age, they also change. Scientists talk about a "life cycle" of a star. A major life-cycle change is how much light energy the star puts out. A star can be "born" after gravity draws together gas and dust in space and packs them tightly. If it's tight enough, the temperature rises to a point that nuclear reactions get going. Boom--the star starts shining. It will keep on shining as long as those reactions keep going inside it. | |
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Answer(s):
[1]
A nuclear reaction is one that releases huge amounts of energy from nuclei of atoms. The type of nuclear reaction in stars is a fusion reaction. In this type, small nuclei combine, or fuse, to form larger ones, releasing energy. In a star, the main such reaction is hydrogen nuclei combining to form helium nuclei. Although nuclei are very small, the energy they contain relative to their size is great. Some of that energy gets released from the nuclear reactions in stars.
| Eventually, though, a star will use up its fuel and burn out. Large stars tend to do that more quickly, the largest in millions of years instead of billions. Scientists expect the sun will burn out, eventually. But don't worry. It takes a very long time for stars the size of the sun to wind down. Unless you are planning to be around for another 5 or 6 billion years, you'll never see any change in the sun. As long as you or anyone close to you will be on Earth, the sun will be there, shining away. | |
This activity is best completed online.
SAFETY: The light bulb will become hot after a short amount of use. Allow time for it to cool before taking it out of the lamp.
| Star Bright Star light, star bright--is the first star you see brighter than the one next to it? Do an experiment to learn that a star's looks may be deceiving. Follow the activity instructions to complete this activity. |
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Lesson Assessment: Stars of the Night Sky
Print this offline assessment and answer key using the links below. You will need to enter your student's results online later.
Click "Print Lesson" button to use your browser print Student Name: Alethea
Date Printed: Jan 11, 2015
Science 3
Unit 11: The Solar System and Beyond
Lesson 5: Stars of the Night Sky
Duration: Approx. 60 min.
There are one or more assessments in this lesson. Offline assessments and answer keys can be printed from the materials lists. Online assessments must be printed from the assessment itself within the lesson.
Firefox cannot print Flash images. The on-screen images might print as blank spaces. If you need to print this lesson, try using Internet Explorer so that all the images print.
For the Adult
*paper, 8 1/2 x 11"
*scissors
*light bulb, 40 watt
*ruler
*tape, clear
*light bulb, 100 watt
*lamp - table (no shade)
*book
Investigation: Star Bright
1 day
Have on hand a 40-watt bulb and a 100-watt bulb for this lesson.
Investigation: Star Bright
The light bulb will become hot after a short amount of use. Allow time for it to cool before taking it out of the lamp.
This activity is best completed online.
| When you look up on a clear night, the sky seems to sparkle with millions of tiny white lights. Almost all these white lights are stars up in space. The stars may look tiny, but they are actually huge. Explore stars and learn how something so big can look so small. | | |||||
| Lesson Overview
|
This activity is best completed online.
| Stars in Space Some stars may appear larger or brighter than others, but are they really? Explore the night sky and find out! | |||||||||
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| Have you ever looked out the rear window of a car as you drove away from a building? You look back and see the building getting smaller and smaller. It isn't really shrinking, but it looks that way because the distance between you and the building is growing. Now imagine zooming away from the sun in a rocket. The farther you go, the smaller the sun looks. As you fly past Jupiter, the sun gets dimmer and dimmer in your rearview mirror. By the time you stop on Pluto, you are 50 times farther away from the sun than you were on Earth. The sun appears only 1/50 as big as from Earth. It's also 1/2500 as bright. Click to compare an Earth scene with what it might look like at Pluto's farthest distance from the sun. | |
|
Answer(s):
[1]
Even though the sun seen from Pluto would have 1/2500 its brightness from Earth, and 1/50 the diameter, it would still be bright. It would be about 180 times the brightness of our full moon. Even the nearest star other than the sun is very much farther away from Pluto than the sun ever is, and would not look nearly as bright as the sun.
| Just as the sun's brightness would depend on its distance, the brightness of all stars depends on how far away they are. That means if two stars are similar, the dimmer one must be farther away. Brightness is affected by things other than distance, though. You could have two stars at the same distance and still have one appear brighter than the other. How? | |
| The brighter star puts out more light energy. It could do that two ways. It could be the same size and brighter. Or it could put out the same energy from any part, but be much bigger. A stadium full of shouting people puts out more energy than one shouting person. Either way, the star giving off more energy will be seen as brighter. If you understand the stadium you can also see that two stars which are close enough together to seem like one will appear brighter than either star alone. Their light adds to make the pair twice as bright. Of course, then three stars together will be even brighter, and ten brighter still. You can see that many stars close together in the sky look brighter than single ones or smaller groups. | |
|
Answer(s):
[1]
Galaxies -- large groups of stars --can have billions of members. our own galazy is estimated to have 100 billion stars. In very far-away galaxies, individual stars may not be visible because of their great distance, but we can still see their light combined as a bright galaxy.
| The first thing you notice about a star is how bright it is. So scientists describe stars by brightness. The system was invented by Hipparchus (huh-PAHR-kuhs), a Greek astronomer. The brightest stars were first magnitude stars, the next brightest second magnitude, and so on. The dimmest ones he could see were sixth magnitude. As scientists developed ways to measure light more exactly, they extended the system to cover stars dimmer than Hipparchus could see and brighter objects than he considered. | |
|
|
Answer(s):
[1]
Brightness, by itself, doesn't tell how far away a star is. A dim star near you might have the same brightness as a bright star far away. That's because, thanks to its distance, the bright one can look smaller and dimmer.
[2]
If your student has trouble understanding magnitude numbers less than zero, point out that they are like temperatures. Very low temperatures are less than zero degrees. Likewise, very bright stars or other objects have magnitudes less than zero. Our sun has magnitude -26.7, and the full moon has magnitude -12.6. At its brightest, Venus has magnitude -4.4.
| Now a visual magnitude number can be between whole numbers, and can be less than 1, even less than zero. It tells you exactly how bright a star looks. Each difference of 1 in magnitude means a multiple of 2½ in brightness. A magnitude 1 star is 2½ times as bright as a magnitude 2 star. A magnitude 2 star is 2½ times as bright as a magnitude 3 star, and so on. | |
|
Answer(s):
[1]
If your student has trouble understanding magnitude numbers less than zero, point out that they are like temperatures. Very low temperatures are less than zero degrees. Likewise, very bright stars or other objects have magnitudes less than zero. Our sun has magnitude -26.7, and the full moon has magnitude -12.6. At its brightest, Venus has magnitude -4.4.
| Our eyes need light to see. The same is true of a camera--you can't take a picture inside a closed dark closet. The dimmer a star is, the harder it is to see, for us or for our tools. Telescopes allow us to see things too dim for our eyes alone. They gather light from a faint star and focus it in one place. It's like funneling more light to the small pupil of your eye. This lets us see things that would otherwise be too dim to make out. | |
|
|
Answer(s):
[1]
Scientists have extended the range of magnitudes beyond 1 through 6. Now we can describe very dim things we can only see with our senstive instruments, as well as very bright things, such as the sun. magnitudes go from -26.7 (the sun) to +30 (the dimmist things we can see with the Hubble Space Telescope). The +30 refers to something 4 billion times fainter than our eyes can make out.
| Telescopes also can make images bigger, which allows us to see details we would not otherwise see, such as on planets or in groups of stars. Photography and other kinds of equipment also help us see light that would be too dim for just our eyes. These inventions greatly increase the number of stars we can see and the details we can learn about them. To direct and focus light, a refracting telescope uses lenses and a reflecting telescope uses mirrors. | |
| So we can describe a star using its magnitude. A lower number means it's brighter. How bright a star appears depends both on how far away it is and how much light it's putting out. It also depends on whether something between the star and us makes it look dimmer. It's harder to see a car's headlights on a foggy night, because the fog is between you and the light. On a hazy day our star, the sun, does not look as bright as on a clear day. | |
| Scientists have several ways to figure out how far away a star is. They may also be able to tell how much of its light is absorbed or reflected by other stuff before it gets here. With that information, they can then use the star's apparent brightness to figure out how much energy it's putting out. That allows scientists to understand what the stars themselves are like, not just how they look from here. | |
| As you get older, you change in lots of ways. Stars get older, too, and as they age, they also change. Scientists talk about a "life cycle" of a star. A major life-cycle change is how much light energy the star puts out. A star can be "born" after gravity draws together gas and dust in space and packs them tightly. If it's tight enough, the temperature rises to a point that nuclear reactions get going. Boom--the star starts shining. It will keep on shining as long as those reactions keep going inside it. | |
|
Answer(s):
[1]
A nuclear reaction is one that releases huge amounts of energy from nuclei of atoms. The type of nuclear reaction in stars is a fusion reaction. In this type, small nuclei combine, or fuse, to form larger ones, releasing energy. In a star, the main such reaction is hydrogen nuclei combining to form helium nuclei. Although nuclei are very small, the energy they contain relative to their size is great. Some of that energy gets released from the nuclear reactions in stars.
| Eventually, though, a star will use up its fuel and burn out. Large stars tend to do that more quickly, the largest in millions of years instead of billions. Scientists expect the sun will burn out, eventually. But don't worry. It takes a very long time for stars the size of the sun to wind down. Unless you are planning to be around for another 5 or 6 billion years, you'll never see any change in the sun. As long as you or anyone close to you will be on Earth, the sun will be there, shining away. | |
This activity is best completed online.
SAFETY: The light bulb will become hot after a short amount of use. Allow time for it to cool before taking it out of the lamp.
| Star Bright Star light, star bright--is the first star you see brighter than the one next to it? Do an experiment to learn that a star's looks may be deceiving. Follow the activity instructions to complete this activity. |
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Lesson Assessment: Stars of the Night Sky
Print this offline assessment and answer key using the links below. You will need to enter your student's results online later.
Click "Print Lesson" button to use your browser print Student Name: Alethea
Date Printed: Jan 11, 2015
Science 3
Unit 11: The Solar System and Beyond
Lesson 1: The Solar System: Planets and Orbits
Duration: Approx. 60 min.
There are one or more assessments in this lesson. Offline assessments and answer keys can be printed from the materials lists. Online assessments must be printed from the assessment itself within the lesson.
Firefox cannot print Flash images. The on-screen images might print as blank spaces. If you need to print this lesson, try using Internet Explorer so that all the images print.
For the Adult
*cherries (4)
*scissors (2)
*honeydew melon (2)
*pea, green (2)
*glue, children's white (2)
*raspberry, small (2)
*cantaloupe (2)
*apple (4)
*index cards (2)
Investigation: Eat Your Way Through the Solar System
1 day
For this Science activity you will need the following food items:
honeydew melon
cantaloupe
apples - 2
cherries - 2
small raspberry
pea
If these items are expensive to buy or difficult to find due to the season, use substitutes of similar size.
honeydew melon
cantaloupe
apples - 2
cherries - 2
small raspberry
pea
If these items are expensive to buy or difficult to find due to the season, use substitutes of similar size.
Lesson 1: The Solar System: Planets and Orbits
| gravity | |
| The attraction between two bodies due to their mass. Gravity provides the force that keeps us planted firmly on the Earth. |
Investigation: Eat Your Way Through the Solar System
This lesson involves eating or working with food. Check with your doctor, if necessary, to find out whether your student will have any allergic reaction to the food.
This activity is best completed online.
| Can you name the eight planets in our solar system? Take an adventure in outer space as you learn about them. You'll find that the planets are different sizes and distances from the sun. Let's blast off! | ||||||||
| Lesson Overview
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This activity is best completed online.
| The Planets You cannot see our solar system all at once. You see the biggest part, the sun, in the daytime. Other parts are visible at night. Some parts cannot be seen easily. How do we know about our solar system? Learn about the solar system and how scientists have studied it. | |||||||||
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| You already know a lot about the sun, Earth, and moon. The Earth revolves around the sun. It takes one year to go around once. The Earth also rotates on its axis, and it takes one day to go around once. The moon revolves around the Earth. That takes about one month. Finally, the moon rotates on its own axis, as the Earth does. The moon rotates more slowly, rotating once in the same time it takes to revolve around the Earth--one month. But the Earth isn't the only planet revolving around the sun. And our moon isn't the only moon revolving around a planet, either. Other planets revolve around our sun, just as we do, with other moons that revolve around those planets. There are even objects revolving around the sun that aren't planets or moons --things such as comets and asteroids. They are all part of what we call the solar system. | |
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| To start with, how do we know about all this stuff in our solar system? The sun and moon are pretty obvious--you can't miss those. But what about the other planets? Have you ever seen one? Actually, you probably have. On a clear night, the sky is full of little lights. Most of them are stars. They are like our sun, only much, much farther away, which is why they look so small. Every now and then, though, you might see a light that isn't a distant star. It might be a lot brighter than any star. It's a planet, and it's right here in our solar system. How do we know the difference? You have to watch carefully, and for a long time, maybe weeks. If you do that, you'll see that planets move across the sky in more complicated paths than stars do. In fact Mars appears to move backwards at times. Sometimes the planets look brighter or dimmer than at other times. Ancient people spent many nights staring at the sky to figure these things out. | |
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Answer(s):
[1]
Things that are far away look small. If you look at a friend two blocks away, you can't make out the details. Similarly, the far away planets and stars look small and we cannot see details without looking through a telescope or going closer.
| So even long ago people knew there were planets in the sky. But everything up there is so far away--how could they see more? Today we know much more, because we have instruments to help us. Just as a microscope lets you see things too tiny for your eyes to make out, a telescope lets you see things very far away as if they were right next door. Other instruments give us new ways to look deeper into the sky as well. Aside from that, people can now go into space--at least a little way. We know a lot about the moon because we've been there. And being able to fly into space means we can get our instruments outside Earth's air. The air can mess up what we see through telescopes. The Hubble Space Telescope, which is in orbit around the Earth, can get super-clear pictures of far-away things. So far, they are much clearer than any picture taken from Earth. | |
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| So what's in the solar system? Solar means sun, which is at the center of the solar system. The sun is a star. It's actually a pretty average-size one--not too big and not too small. Still, it's by far the biggest object in the solar system. In fact, it contains almost all the solar system's mass. If you were the sun, everything else in the solar system together (the Earth, the moon, all the other planets) would have the mass of less than 10 pennies circling around you. Our solar system has eight planets. Starting from the sun and going out, they are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus (YUR-uh-nuhs), and Neptune. They are all very different in size and in distance from the sun. The biggest is Jupiter. The smallest is Mercury. Earth--where you live--is between them in size. | |
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Answer(s):
[1]
Johannes Kepler (1561-1630) discovered three major principles of planetary motion. These principles describe the shapes, sizes, and timing of the planets' orbits around the sun.
| How big are the other things in the solar system, compared to Earth? The sun is the biggest. One hundred and nine Earths could stretch from one side of the sun to the other. The closest planet to the sun, Mercury, is tiny--not much bigger than our moon. Moving out from the sun, Venus is next, only a little bit smaller than Earth in diameter. Then Earth, which is, well...the size of one Earth. After that comes Mars, with about half Earth's diameter. The outer planets are much larger. Jupiter, the largest, has a diameter about eleven times Earth's. Saturn has about nine and a half times Earth's diameter (not including those rings)--almost as big as Jupiter, although Jupiter's much more massive than Saturn. Uranus has four times Earth's diameter, and Neptune is almost the same--just a bit smaller. | |
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| The planets are so far away from Earth that, even reflecting light from the powerful sun, they look like little dots in our sky. And the farthest ones are so distant that they don't even look like dots--we can't see them with our eyes alone. There is lots and lots of empty space between the planets and between each planet and the sun. So how does the solar system stay together? If the planets are so far away, what keeps them from just floating off? You may already know the answer. You may know that a massive object attracts other objects due to gravity. The sun, at the center of the solar system, is so massive that its gravity exerts the main force that holds on to all the planets, even the way, way-out-there ones, such as Neptune. Gravity keeps us all together. It's what makes the solar system a system. | |
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Answer(s):
[1]
Meteoroids are small, rocky objects less than 100km in diameter.
Asteroids are larger rocky objects, 1,000 km or less in diameter, that stay mostly in the region between Mars and Jupiter.
Comets are icy objects that develop "tails" when their path takes them near the sun.
Asteroids are larger rocky objects, 1,000 km or less in diameter, that stay mostly in the region between Mars and Jupiter.
Comets are icy objects that develop "tails" when their path takes them near the sun.
This activity is best completed online.
SAFETY: This lesson involves eating or working with food. Check with your doctor, if necessary, to find out whether your student will have any allergic reaction to the food.
| Eat Your Way Through the Solar System Can you really eat your way through the solar system? No, but you can use different types of food to help you see the relative sizes of all the planets. Print the Eating Your Way Through the Solar System activity sheet if you have not done so already. Follow the activity instructions to complete this activity. |
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This activity is best completed online.
| May I Have Your Order, Please? It's time to become a "Planet Detective." Use clues to help you place the planets in order of their distance from the sun. Print the Planet Clues activity sheet if you have not done so already. Follow the activity instructions to complete this activity. |
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Lesson Assessment: The Solar System: Planets and Orbits
Print this offline assessment and answer key using the links below. You will need to enter your student's results online later.
Click "Print Lesson" button to use your browser print Student Name: Alethea
Date Printed: Jan 11, 2015
Science 3
Unit 11: The Solar System and Beyond
Lesson 2: The Sun
Duration: Approx. 60 min.
There are one or more assessments in this lesson. Offline assessments and answer keys can be printed from the materials lists. Online assessments must be printed from the assessment itself within the lesson.
Firefox cannot print Flash images. The on-screen images might print as blank spaces. If you need to print this lesson, try using Internet Explorer so that all the images print.
This activity is best completed online.
| When you look up in the sky on a bright sunny day, what do you see? The sun! The sun is by far the biggest thing in the whole solar system. It's also the solar system's major source of energy. You have learned about the sun's relationship with Earth and the moon. Now learn more about the sun itself. | | |||||
| Lesson Overview
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This activity is best completed online.
| The Sun Have you ever been sunburned from staying out in the sun for too long? The energy that caused the burn is only a small sample of just how hot and powerful the sun is. Find out more about this amazing, gigantic star. | |||||||||
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| What's the brightest star you've ever seen? No matter who and where you are, the answer is the same. Can you guess? It's the star of this lesson, the sun--our star. We think of stars as tiny points of light we can see only at night, but the sun is a star seen close up. It's so close that it lights up the whole sky and warms up our days. Still, as stars go, the sun's size is average. Stars can be both smaller and much larger. Even if it’s average-sized for a star, our sun is the Earth's biggest source of energy. It's also so massive that its gravity provides the main force keeping all the planets of the solar system together. It may be average compared to other stars, but when you see the sun coming up on a bright morning in spring, you know that the closest star to Earth is also the one that matters most to you. Are you ready to learn more about our sun? | |
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| It's hard to imagine how hot the sun is. If someone told you the sun's surface temperature is 6,000 degrees Celsius, would you believe it? It’s true. Of course, that's how hot it would be if you could measure its surface. Inside the sun, if you could somehow go there with a super-strong thermometer, is more like 15 million degrees Celsius. Now that's hot! Imagining 15 million degrees is almost as hard as imagining how big the sun is. Picture the entire Earth and everything on it. Would all of that fit inside the sun? Yes, it would. So would two Earths, and three, and four. In fact, the sun is so big that 1,300,000 Earths would fit inside it. It would take 109 Earths lined up just to stretch from one side of the sun to the other. Now that's big! | |
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| So what is that big, hot sun made of? Even though it's really massive, the sun is mostly made of hydrogen and helium, the two lightest elements. If they're so light, how can the sun be so massive? By having tons and tons of hydrogen and helium, all packed very tightly in the center. There's also a tiny amount of other elements, including oxygen and carbon. | |
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| The sun's center is called the core. There, the molecules are under a lot of pressure. How much? How does 340 billion times the air pressure on Earth sound? That's enough to crunch hydrogen atoms together and make them into helium--kind of like taking two little snowballs and forcing them together into one. When hydrogen atoms get smooshed into helium, a process called fusion, they release a lot of energy. It's all that crunching and smooshing of hydrogen that keeps the sun glowing. After that energy made by fusion of hydrogen is released, it moves toward the sun's surface, through more layers. When it gets to the surface, it shines out into space. The photosphere is the outside part of the sun we see shining so brightly in the sky. | |
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| Around the whole thing is the corona (kuh-ROH-nuh). If you drew a cartoon of the sun as a circle with flames all around it, the corona would be those flames. You can see it well when there's an eclipse, because the moon blocks everything else. But when the moon isn't in the way, the photosphere, much brighter than the corona, is the more obvious layer. That's why you see the photosphere as the surface of the sun. But don't try to look at the sun directly, even during an eclipse. The sun's tremendous energy is dangerous to your eyes. | |
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Answer(s):
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In 1903, Bernard Lyot found a way to look at the corona even without an actual eclipse. His coronagraph makes an artifical exclipse by blocking out the light from everything but the corona.
| From here on Earth the sun seems always about the same. Cloudy days come and go, but the sun is always the sun, shining away as usual. Actually, though, that's not exactly right. A lot of changes happen in the sun, even if we don't notice them. Scientists who study the sun with many different instruments find that it has a "stormy" surface. Not thunder and lightning, but gigantic flares of energy shoot out of the sun from time to time. Such explosions send out X-rays and radio waves that can cause trouble for radio communication here on Earth. Still, even if the sun is stormy, it's reliable. Scientists think it has been around for billions of years and will be around for billions more. As long as you or anyone close to you is here to enjoy it, you can expect the sun to be up in the sky--bright, warm, and sending us energy for life. | |
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This activity is best completed online.
| My Solar System Book In the next few lessons you will be creating a book about the entire solar system. Begin your book by drawing the sun, labeling the layers and writing down other important facts you have learned about it. Print the My Solar System Book activity sheet if you have not done so already. Follow the activity instructions to complete this activity. |
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Lesson Assessment: The Sun
Print this offline assessment and answer key using the links below. You will need to enter your student's results online later.
Click "Print Lesson" button to use your browser print Student Name: Alethea
Date Printed: Jan 11, 2015
Science 3
Unit 11: The Solar System and Beyond
Lesson 3: The Inner Planets
Duration: Approx. 60 min.
There are one or more assessments in this lesson. Offline assessments and answer keys can be printed from the materials lists. Online assessments must be printed from the assessment itself within the lesson.
Firefox cannot print Flash images. The on-screen images might print as blank spaces. If you need to print this lesson, try using Internet Explorer so that all the images print.
For the Adult
*tape, clear
*scissors
*toilet paper - rolls (3)
Investigation: My Solar System Book, Part 2
1 day
Have on hand the pages about the sun that your student created in the previous lesson, The Sun. Also, gather the pages of My Solar System Book from earlier lessons in this unit.
Investigation: Make a Model of the Solar System
1 day
For today's lesson you will need the pictures of the planets on index cards, which you used in the first lesson of the unit.
Lesson 3: The Inner Planets
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| Earth-like, made mainly of rock and metal, with a solid surface. The terrestrial surface of the planet made it easy for the astronauts to walk there. |
This activity is best completed online.
| You have learned that eight planets orbit the sun. The four planets closest to the sun are similar in many ways, but they also have big differences. Begin your planetary journey by visiting these inner planets to learn what they're like. | | |||||||
| Lesson Overview
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This activity is best completed online.
| The Inner Planets The inner planets are the four planets closest to the sun. Find out what Mercury, Venus, Earth, and Mars have in common, what makes them so different from most of the other planets, and how they differ from one another. | |||||||||
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| You've learned about the enormous size of the sun and the huge amount of energy it releases. You have also learned a little about the planets. The four planets closest to the sun are Mercury, Venus, Earth, and Mars. They are called the inner planets because they are closest to the sun. They have some other things in common that are different from the giant and gaseous outer planets Jupiter, Saturn, Uranus and Neptune. The inner planets are all terrestrial, meaning that they are made mainly of rock and metal. They are solid, not gaseous. They rotate fairly slowly, and have no rings and few natural satellites, or moons. They are the size of the Earth or smaller, less than 13,000 km in diameter. | |
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Answer(s):
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One factor that helps knowledge advance is improvements in tools and methods. Before Galileo built a telescope, people could observe other planets with only their eyes. Only five planets were bright enough to be seen.
| Mercury is the planet closest to the sun. Viewed from Earth, it goes through phases as it moves, like the moon. It's like our moon in many other ways, too. It's the smallest planet, with a diameter only 1 1/2 times the moon's. Being small with little gravity and very hot, Mercury doesn't have an atmosphere. That means there is no air for weather, and craters stay for a long time. | |
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Answer(s):
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The space probe Mariner 10 flew by Mercury three times in 1974 and 1975. Its closest point brought it within about 320 km. (200 mi.) of the planet. It brought back to Earth the first close-up pictures of Mercury and information about its atmosphere.
| Mercury's orbit around the sun is far from circular. Its distance from the sun can be from 46 million km. to 70 million km. Being so near the sun, it's hot there during the day. Temperatures can rise to 467°C (about 870°F)--much hotter than your oven! With no atmosphere to keep heat in, at night it can be -173°C (-280°F)--much colder than a freezer. Also, nights can be long, a whole Mercury year in some places--88 Earth days! Heat absorbed during the day has plenty of time to leave. | |
| Venus is the planet second-closest to the sun. In 1610 Galileo, discovered that, viewed from Earth, Venus has phases just like the moon. This discovery provided evidence for Copernicus's argument that the sun, not the Earth, is the center of the solar system. | |
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Answer(s):
[1]
Two spacecrafts, Mariner 2 (1962) and Mariner 5 (1967), passed within 34,800 km (21,600 mi) and 3,990 km (2,480 mi) of Venus, respectively. They measured its temperature and atmosphere. In the 1970s and 1980s, Soviet spacecrafts actually landed there and sent back information about the atmosphere and the surface.
| Venus is in some ways very similar to the Earth. It has almost the same diameter. Its surface is made of similar material--it's dry and rocky, with mountains and active volcanoes. But it's very different in some ways. There are no oceans and, in fact, no water. Temperatures are hot enough to melt lead. And Venus has a very dense atmosphere that keeps the sun's heat energy in. The atmosphere is almost all carbon dioxide, and its pressure is 90 times the air pressure on Earth! High above the surface are fast-moving clouds made of sulfuric acid, not water. Down near the surface, the winds are slow. | |
| Imagine visiting Earth. Well, you don't have to, because you live here. But imagine visiting here from somewhere else, so that everything you see on Earth is new to you. Your first thought might be: It sure has lots of water! It's mostly seawater, which covers 71 percent--nearly three-quarters--of the planet. It's the only planet known to have liquid water. Its temperature averages about 20°C--a good temperature for liquid water, not near the freezing or boiling points. | |
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| Earth has mountains, plains, valleys, rivers, streams, and lakes. The atmosphere is mostly nitrogen, with a lot of oxygen, and smaller amounts of other substances. The tilt of the axis of rotation of the Earth causes seasons of warm and cold weather, even though its orbit around the sun is almost circular. And don't forget life. Everywhere there's green plants and weird animals! The Earth is a living planet! | |
| Years ago, people thought that there might be life on Mars, too. Recent visits to Mars show us that no obvious life is there now. But Mars has water--not liquid, but frozen, just under the surface. Temperatures are mostly like a very cold freezer's. Mars is about 1 1/2 times as far from the sun as Earth is, and has about half the diameter. Its axis is tilted like Earth's, by about the same amount, so Mars has seasons. Days are about the same length as Earth days, but years are almost twice as long as Earth's. | |
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Answer(s):
[1]
Between 1965 and 1972, four Mariner spacecraft photographed the surface of Mars and analyzed its atmosphere. More recent craft have landed on Mars, sending back photos and analyzing rocks.
| Polar ice caps grow and shrink with changing seasons. Huge canyons indicate that lots of liquid water was once on Mars. As on Venus, the atmosphere is mostly carbon dioxide. But unlike Venus, the atmosphere on Mars is very light--much less than on Earth. Still, there's enough atmosphere for dust storms, which are common on Mars. | |
| Mercury - Venus - Earth - Mars. Those are the four inner planets. Venus and Earth are similar in size and made of similar matter, but Venus is much hotter and has a much denser atmosphere. Mercury, closest to the sun, is very much like the moon in some ways: it has no atmosphere and is very hot during its very long day, and very cold during its very long night. Mars is half the size of the Earth, and farther from the sun. It's cold, has days about the length of Earth days, seasons, and has water in the form of ice. And Earth has life! All these inner planets are very different from the four gas-giant outer planets that we'll learn about next. The outer planets are far out! | |
This activity is best completed online.
| My Solar System Book, Part 2 The four inner planets have characteristics in common, and each has characteristics that make it unique. Think about both types of characteristics as you add the inner planets to your solar system book. Print the My Solar System Book activity sheet if you have not done so already. Follow the activity instructions to complete this activity. |
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This activity is best completed online.
| Make a Model of the Solar System Just how far are the inner planets from the sun? A roll of toilet paper can help you understand! Print the Planet Distances Chart activity sheet if you have not done so already. Follow the activity instructions to complete this activity |
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Lesson Assessment: The Inner Planets
This assessment is best completed online, where it will be automatically scored by the computer. If you would like to print it, do so from the assessment itself within the lesson.
Click "Print Lesson" button to use your browser print Student Name: Alethea
Date Printed: Jan 11, 2015
Science 3
Unit 11: The Solar System and Beyond
Lesson 4: The Outer Planets
Duration: Approx. 60 min.
There are one or more assessments in this lesson. Offline assessments and answer keys can be printed from the materials lists. Online assessments must be printed from the assessment itself within the lesson.
Firefox cannot print Flash images. The on-screen images might print as blank spaces. If you need to print this lesson, try using Internet Explorer so that all the images print.
For the Adult
*pencils, colored 12
*toilet paper - rolls (2)
*scissors
*stapler
Investigation: My Solar System Book, Part 3
1 day
Have on hand the pages about the sun and the inner planets that your student created in the previous lessons. Also, gather the pages of My Solar System Book from the previous lessons.
Investigation: Make a Model of the Solar System, Part 2
1 day
Have on hand the toilet-paper strips representing the distances from the sun of the inner planets. For today's lesson you will need the planets cards you used in the first lesson of the unit. Also, gather the previous work of the toilet-paper model.
This activity is best completed online.
| Continue your planet journey as you travel farther away from the sun to the outer planets. See what makes these planets different from the inner planets, and how they compare to one another. | | |||||||
| Lesson Overview
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This activity is best completed online.
| Far Out! Are you ready to learn about the giants of the solar system? You will find that the four outer planets are very different from the inner planets. | |||||||||
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| In the rocket of your imagination you've visited the four inner planets: Mercury, Venus, Earth, and Mars. You learned about their sizes, their distance from the sun, and their day lengths. Now let's go deeper into space. The four outer planets are much larger than the inner planets. What's also different is that their surfaces are not solid. They're made of gas, like huge, dense clouds. That's why Saturn, Jupiter, Uranus, and Neptune are called gas giants. Their moons are solid enough, though, and they all have plenty of moons, and rings. | |
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Answer(s):
[1]
Uranus and Neptune are so far out and hard to see, that no one knew they were there until telescopes were invented. But if conditions are just right it's sometimes possbile to see Uranus.
| Other objects, smaller than planets, also orbit the sun. Many are in big collections called belts. One of these belts is between Mars and Jupiter. The other is beyond Neptune. But the real show is the giants of the solar system. Are you ready to play with the big kids--the outer planets? | |
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| As your rocket goes out past Mars, the first gas giant you reach is also the doozy of them all. Jupiter is the biggest. It's over twice as massive as all the others combined. In fact, it's like a little star, except it's not putting out light. But it does put out heat. It would have become a star if it were a little bigger. Jupiter's atmosphere is mainly hydrogen and helium, which stars are made of. | |
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Answer(s):
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An asteroid belt exists between the inner planets and outer planets, specifically between the orbits of Mars and Jupiter. Asteroids have an irregular shape and are smaller than planets. The largest is about 1000 km. across. They are referred to as planetoids. The asteroid belt is between the inner planets and the outer ones.
| Like a star, Jupiter has no solid surface. Instead, it is made of thick gases, becoming a dense, hot liquid toward the center. The very center is rocky, possibly molten (melted). It even has its own "mini-solar system"--67 known moons and more being discovered on a regular basis. Many are very small--less than 4 km across--but four are large, and one is larger than Mercury. Jupiter is like an almost-star surrounded by almost-planets. Jupiter rotates in 10 hours. It takes about 12 Earth years to orbit the sun. It has rings of small particles and dust. | |
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| Next you come to Saturn, with the most spectacular, biggest rings. Saturn's huge, too. It's almost as big as Jupiter, but has only 1/3 Jupiter's mass. That makes it the least dense of the gas giants. Like Jupiter, Saturn is made mostly of hydrogen, and has no surface you could land on. It has clouds of ammonia on top and high-pressure liquid inside, with a rocky core. Saturn's cold, too. In the atmosphere the temperature gets down to -190°C. Things get hotter as you move in deeper. | |
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Answer(s):
[1]
Passing near Saturn, Pioneer 11 (in 1979) and Voyagers 1 and 2 (in 1980 and 1981) have provided much useful information about the planet. In 2001, Mars Odyssey was put into orbit around Saturn to help us learn even more.
[2]
If your student is confused by the idea of a planet not having a surface, explain that Saturn only has a surface in the same sense that a cloud in the sky does. It ends at a certain place, but if you tried to land a spaceship on it you would sail right through.
| Saturn has at least 30 moons. The biggest is bigger than Mercury, like a planet itself. Best of all, though, Saturn has those terrific rings. Jupiter, Uranus, and Neptune have rings, too, but Saturn's are the most visible and well known. If you could steer your rocket close you'd find the rings are made of ice chunks. Some are beach-ball size, some smaller. The rings only look solid from far away. | |
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| Next comes Uranus. Like the others, it's made of gas, with liquid and a rocky core down deep. It's also mostly hydrogen and helium. Uranus has rings, too--11 of them--and 21 known moons. The strangest thing is its axis of rotation. It's tipped entirely over, rotating ''on its side.'' That means it has dramatic seasons. Each season is about 21 Earth years. Imagine it near the poles. In one season, the sun does not set for many Earth years. Next season it rises and sets every 17 hours! Then it doesn't rise again for years. Even so, Uranus is so far from the sun that it's always very cold. | |
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Answer(s):
[1]
Voyager 2 flew by Uranus in 1986, and gathered information about the planet's rotation and structure.
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Your student can get a sense of Uranus's rotation ''on its side'' by lifting a globe up by its axis, holding the axis horizontally and having someone else spin the globe. (You could use an orange with an axis, with a pin for location on it, as for the lesson on The Seasons.) You can demonstrate the times between sunrise and sunset in different seasons and on different parts of Uranus by moving it around a central object (bare lightbulb) representing the sun, keeping the globe in the same orientation with respect to the room.
A pea 5 mm in diameter held 10 meters away would have the visual diameter of the sun from Uranus. It still would be very bright, even if just 1/400 the brightness of the sun we know. It would still have about 1100 times the brightness of our full moon.
A pea 5 mm in diameter held 10 meters away would have the visual diameter of the sun from Uranus. It still would be very bright, even if just 1/400 the brightness of the sun we know. It would still have about 1100 times the brightness of our full moon.
| We're getting really far out now. In your imagination, stop your rocket and take a look back. Since Uranus is 20 times farther from the sun than Earth, the sun will only appear 1/20 as big across and 1/400 as bright. Can you imagine the sun looking like a bright pea in the sky? | |
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Answer(s):
[1]
Your student can get a sense of Uranus's rotation ''on its side'' by lifting a globe up by its axis, holding the axis horizontally and having someone else spin the globe. (You could use an orange with an axis, with a pin for location on it, as for the lesson on The Seasons.) You can demonstrate the times between sunrise and sunset in different seasons and on different parts of Uranus by moving it around a central object (bare lightbulb) representing the sun, keeping the globe in the same orientation with respect to the room.
A pea 5 mm in diameter held 10 meters away would have the visual diameter of the sun from Uranus. It still would be very bright, even if just 1/400 the brightness of the sun we know. It would still have about 1100 times the brightness of our full moon.
A pea 5 mm in diameter held 10 meters away would have the visual diameter of the sun from Uranus. It still would be very bright, even if just 1/400 the brightness of the sun we know. It would still have about 1100 times the brightness of our full moon.
| Neptune is the gas giant that is farthest from the sun. It's so far out it wasn't discovered until 1846. You can't see it without a telescope. Neptune takes almost 165 Earth years to orbit the sun, so it has only had one complete Neptune year since its discovery. Neptune is very cold but it releases its own heat, which warms it up a little. Neptune is the stormiest planet with the fastest winds, which blow at thousands of kilometers per hour. | |
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Answer(s):
[1]
Voyager 2 in 1989 discovered six of Neptune's thirteen known moons.
| Looking out your rocket's window, the first thing you notice about Neptune is its beauty! It has a rich, deep blue color, like a drop of ocean water. That's the atmosphere. It's mostly hydrogen and helium, but some methane absorbs red light, giving it that wonderful blue color. Neptune has rings, thirteen known moons, and seasons due to a tilted axis. Well, the seasons are 41 years long, 1/4 its year. That's a long winter, but it's always cold. | |
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| Wait a minute! What about Pluto? Isn't that a planet? From the first time Pluto was found, some scientists thought tiny Pluto shouldn't be called a planet. It was always an oddball. For example, it's smaller than our moon, even though it has its own moon, Charon (KAIR-uhn), about half the diameter of Pluto itself. Also, its orbit is much less circular than those of the other planets. It swings in closer to the sun and then farther out again. After years of debate, scientists decided in 2006 that Pluto was not a true planet; instead Pluto is considered a "dwarf planet." | |
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Answer(s):
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In a region beyond Neptune, comets, asteroids, and other objects orbit the sun. In 2002 a planet-like object, with about half Pluto's diameter, was found there and named Quaoar. Scientists debate whether it should be called a planet, as well as whether Pluto should be. Several others like it have also been found.
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The sun from Earth is about the visual size of a centimeter held a meter away, like a penny (about 2 cm) held 2 meters away (try it), or a 5 mm diameter pea held ½ meter away. So being 1/50 the size, like from Pluto, means it would be like 1/5 mm held a meter away, less than half a mm held 2 meters away, or a 5 mm diameter pea held 25 meters away. These are very small dots. Nevertheless, it would still shine with about 180 times the brightness of our full moon from just this tiny point.
| Whatever you call it, land on Pluto and have a final look back. The sun looks 1/50 its diameter from Earth, 1/2500 as bright. It's brighter than our full moon, but tiny. Does that make you feel lonely for home--or does it make you want to travel more, to see all those other suns? | |
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This activity is best completed online.
| My Solar System Book, Part 3 Complete your My Solar System Book by adding pictures and descriptions of the five outer planets. Print the My Solar System Book activity sheet if you have not done so already. Follow the activity instructions to complete this activity. |
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This activity is best completed online.
| Make a Model of the Solar System, Part 2 Add the outer planets to your toilet-paper model to show how far these planets are from the sun compared to each other and compared to the inner planets. Print the Planet Distances Chart activity sheet if you have not done so already. Follow the activity instructions to complete this activity. |
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Lesson Assessment: The Outer Planets
This assessment is best completed online, where it will be automatically scored by the computer. If you would like to print it, do so from the assessment itself within the lesson.
Click "Print Lesson" button to use your browser print Student Name: Alethea
Date Printed: Jan 11, 2015
Science 3
Unit 11: The Solar System and Beyond
Lesson 5: Stars of the Night Sky
Duration: Approx. 60 min.
There are one or more assessments in this lesson. Offline assessments and answer keys can be printed from the materials lists. Online assessments must be printed from the assessment itself within the lesson.
Firefox cannot print Flash images. The on-screen images might print as blank spaces. If you need to print this lesson, try using Internet Explorer so that all the images print.
For the Adult
*paper, 8 1/2 x 11"
*scissors
*light bulb, 40 watt
*ruler
*tape, clear
*light bulb, 100 watt
*lamp - table (no shade)
*book
Investigation: Star Bright
1 day
Have on hand a 40-watt bulb and a 100-watt bulb for this lesson.
Investigation: Star Bright
The light bulb will become hot after a short amount of use. Allow time for it to cool before taking it out of the lamp.
This activity is best completed online.
| When you look up on a clear night, the sky seems to sparkle with millions of tiny white lights. Almost all these white lights are stars up in space. The stars may look tiny, but they are actually huge. Explore stars and learn how something so big can look so small. | | |||||
| Lesson Overview
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This activity is best completed online.
| Stars in Space Some stars may appear larger or brighter than others, but are they really? Explore the night sky and find out! | |||||||||
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| Have you ever looked out the rear window of a car as you drove away from a building? You look back and see the building getting smaller and smaller. It isn't really shrinking, but it looks that way because the distance between you and the building is growing. Now imagine zooming away from the sun in a rocket. The farther you go, the smaller the sun looks. As you fly past Jupiter, the sun gets dimmer and dimmer in your rearview mirror. By the time you stop on Pluto, you are 50 times farther away from the sun than you were on Earth. The sun appears only 1/50 as big as from Earth. It's also 1/2500 as bright. Click to compare an Earth scene with what it might look like at Pluto's farthest distance from the sun. | |
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Answer(s):
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Even though the sun seen from Pluto would have 1/2500 its brightness from Earth, and 1/50 the diameter, it would still be bright. It would be about 180 times the brightness of our full moon. Even the nearest star other than the sun is very much farther away from Pluto than the sun ever is, and would not look nearly as bright as the sun.
| Just as the sun's brightness would depend on its distance, the brightness of all stars depends on how far away they are. That means if two stars are similar, the dimmer one must be farther away. Brightness is affected by things other than distance, though. You could have two stars at the same distance and still have one appear brighter than the other. How? | |
| The brighter star puts out more light energy. It could do that two ways. It could be the same size and brighter. Or it could put out the same energy from any part, but be much bigger. A stadium full of shouting people puts out more energy than one shouting person. Either way, the star giving off more energy will be seen as brighter. If you understand the stadium you can also see that two stars which are close enough together to seem like one will appear brighter than either star alone. Their light adds to make the pair twice as bright. Of course, then three stars together will be even brighter, and ten brighter still. You can see that many stars close together in the sky look brighter than single ones or smaller groups. | |
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Answer(s):
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Galaxies -- large groups of stars --can have billions of members. our own galazy is estimated to have 100 billion stars. In very far-away galaxies, individual stars may not be visible because of their great distance, but we can still see their light combined as a bright galaxy.
| The first thing you notice about a star is how bright it is. So scientists describe stars by brightness. The system was invented by Hipparchus (huh-PAHR-kuhs), a Greek astronomer. The brightest stars were first magnitude stars, the next brightest second magnitude, and so on. The dimmest ones he could see were sixth magnitude. As scientists developed ways to measure light more exactly, they extended the system to cover stars dimmer than Hipparchus could see and brighter objects than he considered. | |
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Answer(s):
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Brightness, by itself, doesn't tell how far away a star is. A dim star near you might have the same brightness as a bright star far away. That's because, thanks to its distance, the bright one can look smaller and dimmer.
[2]
If your student has trouble understanding magnitude numbers less than zero, point out that they are like temperatures. Very low temperatures are less than zero degrees. Likewise, very bright stars or other objects have magnitudes less than zero. Our sun has magnitude -26.7, and the full moon has magnitude -12.6. At its brightest, Venus has magnitude -4.4.
| Now a visual magnitude number can be between whole numbers, and can be less than 1, even less than zero. It tells you exactly how bright a star looks. Each difference of 1 in magnitude means a multiple of 2½ in brightness. A magnitude 1 star is 2½ times as bright as a magnitude 2 star. A magnitude 2 star is 2½ times as bright as a magnitude 3 star, and so on. | |
|
Answer(s):
[1]
If your student has trouble understanding magnitude numbers less than zero, point out that they are like temperatures. Very low temperatures are less than zero degrees. Likewise, very bright stars or other objects have magnitudes less than zero. Our sun has magnitude -26.7, and the full moon has magnitude -12.6. At its brightest, Venus has magnitude -4.4.
| Our eyes need light to see. The same is true of a camera--you can't take a picture inside a closed dark closet. The dimmer a star is, the harder it is to see, for us or for our tools. Telescopes allow us to see things too dim for our eyes alone. They gather light from a faint star and focus it in one place. It's like funneling more light to the small pupil of your eye. This lets us see things that would otherwise be too dim to make out. | |
|
|
Answer(s):
[1]
Scientists have extended the range of magnitudes beyond 1 through 6. Now we can describe very dim things we can only see with our senstive instruments, as well as very bright things, such as the sun. magnitudes go from -26.7 (the sun) to +30 (the dimmist things we can see with the Hubble Space Telescope). The +30 refers to something 4 billion times fainter than our eyes can make out.
| Telescopes also can make images bigger, which allows us to see details we would not otherwise see, such as on planets or in groups of stars. Photography and other kinds of equipment also help us see light that would be too dim for just our eyes. These inventions greatly increase the number of stars we can see and the details we can learn about them. To direct and focus light, a refracting telescope uses lenses and a reflecting telescope uses mirrors. | |
| So we can describe a star using its magnitude. A lower number means it's brighter. How bright a star appears depends both on how far away it is and how much light it's putting out. It also depends on whether something between the star and us makes it look dimmer. It's harder to see a car's headlights on a foggy night, because the fog is between you and the light. On a hazy day our star, the sun, does not look as bright as on a clear day. | |
| Scientists have several ways to figure out how far away a star is. They may also be able to tell how much of its light is absorbed or reflected by other stuff before it gets here. With that information, they can then use the star's apparent brightness to figure out how much energy it's putting out. That allows scientists to understand what the stars themselves are like, not just how they look from here. | |
| As you get older, you change in lots of ways. Stars get older, too, and as they age, they also change. Scientists talk about a "life cycle" of a star. A major life-cycle change is how much light energy the star puts out. A star can be "born" after gravity draws together gas and dust in space and packs them tightly. If it's tight enough, the temperature rises to a point that nuclear reactions get going. Boom--the star starts shining. It will keep on shining as long as those reactions keep going inside it. | |
|
Answer(s):
[1]
A nuclear reaction is one that releases huge amounts of energy from nuclei of atoms. The type of nuclear reaction in stars is a fusion reaction. In this type, small nuclei combine, or fuse, to form larger ones, releasing energy. In a star, the main such reaction is hydrogen nuclei combining to form helium nuclei. Although nuclei are very small, the energy they contain relative to their size is great. Some of that energy gets released from the nuclear reactions in stars.
| Eventually, though, a star will use up its fuel and burn out. Large stars tend to do that more quickly, the largest in millions of years instead of billions. Scientists expect the sun will burn out, eventually. But don't worry. It takes a very long time for stars the size of the sun to wind down. Unless you are planning to be around for another 5 or 6 billion years, you'll never see any change in the sun. As long as you or anyone close to you will be on Earth, the sun will be there, shining away. | |
This activity is best completed online.
SAFETY: The light bulb will become hot after a short amount of use. Allow time for it to cool before taking it out of the lamp.
| Star Bright Star light, star bright--is the first star you see brighter than the one next to it? Do an experiment to learn that a star's looks may be deceiving. Follow the activity instructions to complete this activity. |
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Lesson Assessment: Stars of the Night Sky
Print this offline assessment and answer key using the links below. You will need to enter your student's results online later.
Click "Print Lesson" button to use your browser print Student Name: Alethea
Date Printed: Jan 11, 2015
Science 3
Unit 11: The Solar System and Beyond
Lesson 5: Stars of the Night Sky
Duration: Approx. 60 min.
There are one or more assessments in this lesson. Offline assessments and answer keys can be printed from the materials lists. Online assessments must be printed from the assessment itself within the lesson.
Firefox cannot print Flash images. The on-screen images might print as blank spaces. If you need to print this lesson, try using Internet Explorer so that all the images print.
For the Adult
*paper, 8 1/2 x 11"
*scissors
*light bulb, 40 watt
*ruler
*tape, clear
*light bulb, 100 watt
*lamp - table (no shade)
*book
Investigation: Star Bright
1 day
Have on hand a 40-watt bulb and a 100-watt bulb for this lesson.
Investigation: Star Bright
The light bulb will become hot after a short amount of use. Allow time for it to cool before taking it out of the lamp.
This activity is best completed online.
| When you look up on a clear night, the sky seems to sparkle with millions of tiny white lights. Almost all these white lights are stars up in space. The stars may look tiny, but they are actually huge. Explore stars and learn how something so big can look so small. | | |||||
| Lesson Overview
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This activity is best completed online.
| Stars in Space Some stars may appear larger or brighter than others, but are they really? Explore the night sky and find out! | |||||||||
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| Have you ever looked out the rear window of a car as you drove away from a building? You look back and see the building getting smaller and smaller. It isn't really shrinking, but it looks that way because the distance between you and the building is growing. Now imagine zooming away from the sun in a rocket. The farther you go, the smaller the sun looks. As you fly past Jupiter, the sun gets dimmer and dimmer in your rearview mirror. By the time you stop on Pluto, you are 50 times farther away from the sun than you were on Earth. The sun appears only 1/50 as big as from Earth. It's also 1/2500 as bright. Click to compare an Earth scene with what it might look like at Pluto's farthest distance from the sun. | |
|
Answer(s):
[1]
Even though the sun seen from Pluto would have 1/2500 its brightness from Earth, and 1/50 the diameter, it would still be bright. It would be about 180 times the brightness of our full moon. Even the nearest star other than the sun is very much farther away from Pluto than the sun ever is, and would not look nearly as bright as the sun.
| Just as the sun's brightness would depend on its distance, the brightness of all stars depends on how far away they are. That means if two stars are similar, the dimmer one must be farther away. Brightness is affected by things other than distance, though. You could have two stars at the same distance and still have one appear brighter than the other. How? | |
| The brighter star puts out more light energy. It could do that two ways. It could be the same size and brighter. Or it could put out the same energy from any part, but be much bigger. A stadium full of shouting people puts out more energy than one shouting person. Either way, the star giving off more energy will be seen as brighter. If you understand the stadium you can also see that two stars which are close enough together to seem like one will appear brighter than either star alone. Their light adds to make the pair twice as bright. Of course, then three stars together will be even brighter, and ten brighter still. You can see that many stars close together in the sky look brighter than single ones or smaller groups. | |
|
Answer(s):
[1]
Galaxies -- large groups of stars --can have billions of members. our own galazy is estimated to have 100 billion stars. In very far-away galaxies, individual stars may not be visible because of their great distance, but we can still see their light combined as a bright galaxy.
| The first thing you notice about a star is how bright it is. So scientists describe stars by brightness. The system was invented by Hipparchus (huh-PAHR-kuhs), a Greek astronomer. The brightest stars were first magnitude stars, the next brightest second magnitude, and so on. The dimmest ones he could see were sixth magnitude. As scientists developed ways to measure light more exactly, they extended the system to cover stars dimmer than Hipparchus could see and brighter objects than he considered. | |
|
|
Answer(s):
[1]
Brightness, by itself, doesn't tell how far away a star is. A dim star near you might have the same brightness as a bright star far away. That's because, thanks to its distance, the bright one can look smaller and dimmer.
[2]
If your student has trouble understanding magnitude numbers less than zero, point out that they are like temperatures. Very low temperatures are less than zero degrees. Likewise, very bright stars or other objects have magnitudes less than zero. Our sun has magnitude -26.7, and the full moon has magnitude -12.6. At its brightest, Venus has magnitude -4.4.
| Now a visual magnitude number can be between whole numbers, and can be less than 1, even less than zero. It tells you exactly how bright a star looks. Each difference of 1 in magnitude means a multiple of 2½ in brightness. A magnitude 1 star is 2½ times as bright as a magnitude 2 star. A magnitude 2 star is 2½ times as bright as a magnitude 3 star, and so on. | |
|
Answer(s):
[1]
If your student has trouble understanding magnitude numbers less than zero, point out that they are like temperatures. Very low temperatures are less than zero degrees. Likewise, very bright stars or other objects have magnitudes less than zero. Our sun has magnitude -26.7, and the full moon has magnitude -12.6. At its brightest, Venus has magnitude -4.4.
| Our eyes need light to see. The same is true of a camera--you can't take a picture inside a closed dark closet. The dimmer a star is, the harder it is to see, for us or for our tools. Telescopes allow us to see things too dim for our eyes alone. They gather light from a faint star and focus it in one place. It's like funneling more light to the small pupil of your eye. This lets us see things that would otherwise be too dim to make out. | |
|
|
Answer(s):
[1]
Scientists have extended the range of magnitudes beyond 1 through 6. Now we can describe very dim things we can only see with our senstive instruments, as well as very bright things, such as the sun. magnitudes go from -26.7 (the sun) to +30 (the dimmist things we can see with the Hubble Space Telescope). The +30 refers to something 4 billion times fainter than our eyes can make out.
| Telescopes also can make images bigger, which allows us to see details we would not otherwise see, such as on planets or in groups of stars. Photography and other kinds of equipment also help us see light that would be too dim for just our eyes. These inventions greatly increase the number of stars we can see and the details we can learn about them. To direct and focus light, a refracting telescope uses lenses and a reflecting telescope uses mirrors. | |
| So we can describe a star using its magnitude. A lower number means it's brighter. How bright a star appears depends both on how far away it is and how much light it's putting out. It also depends on whether something between the star and us makes it look dimmer. It's harder to see a car's headlights on a foggy night, because the fog is between you and the light. On a hazy day our star, the sun, does not look as bright as on a clear day. | |
| Scientists have several ways to figure out how far away a star is. They may also be able to tell how much of its light is absorbed or reflected by other stuff before it gets here. With that information, they can then use the star's apparent brightness to figure out how much energy it's putting out. That allows scientists to understand what the stars themselves are like, not just how they look from here. | |
| As you get older, you change in lots of ways. Stars get older, too, and as they age, they also change. Scientists talk about a "life cycle" of a star. A major life-cycle change is how much light energy the star puts out. A star can be "born" after gravity draws together gas and dust in space and packs them tightly. If it's tight enough, the temperature rises to a point that nuclear reactions get going. Boom--the star starts shining. It will keep on shining as long as those reactions keep going inside it. | |
|
Answer(s):
[1]
A nuclear reaction is one that releases huge amounts of energy from nuclei of atoms. The type of nuclear reaction in stars is a fusion reaction. In this type, small nuclei combine, or fuse, to form larger ones, releasing energy. In a star, the main such reaction is hydrogen nuclei combining to form helium nuclei. Although nuclei are very small, the energy they contain relative to their size is great. Some of that energy gets released from the nuclear reactions in stars.
| Eventually, though, a star will use up its fuel and burn out. Large stars tend to do that more quickly, the largest in millions of years instead of billions. Scientists expect the sun will burn out, eventually. But don't worry. It takes a very long time for stars the size of the sun to wind down. Unless you are planning to be around for another 5 or 6 billion years, you'll never see any change in the sun. As long as you or anyone close to you will be on Earth, the sun will be there, shining away. | |
This activity is best completed online.
SAFETY: The light bulb will become hot after a short amount of use. Allow time for it to cool before taking it out of the lamp.
| Star Bright Star light, star bright--is the first star you see brighter than the one next to it? Do an experiment to learn that a star's looks may be deceiving. Follow the activity instructions to complete this activity. |
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Lesson Assessment: Stars of the Night Sky
Print this offline assessment and answer key using the links below. You will need to enter your student's results online later.
Click "Print Lesson" button to use your browser print Student Name: Alethea
Date Printed: Jan 11, 2015
Science 3
Unit 11: The Solar System and Beyond
Lesson 6: Constellations: Star Patterns
Duration: Approx. 60 min.
There are one or more assessments in this lesson. Offline assessments and answer keys can be printed from the materials lists. Online assessments must be printed from the assessment itself within the lesson.
Firefox cannot print Flash images. The on-screen images might print as blank spaces. If you need to print this lesson, try using Internet Explorer so that all the images print.
For the Adult
*flashlight
*aluminum foil
*bowl - clear glass
*water
*stickers - gold stars
*umbrella
Investigation: Sky Umbrella
1 day
Be sure to have stickers of gold stars on hand for this activity.
Lesson 6: Constellations: Star Patterns
| | Betelgeuse [BEE-tl-joos] |
| |
| constellation | |
| a group of stars that forms a pattern in the sky; Orion is a constellation |
| | Orion [uh-RIY-uhn] |
| |
| | Polaris [puh-LAIR-uhs] |
| a star directly above the North Pole in line with the Earth's axis; also called the North Star |
| | Ptolemy [TAH-luh-mee] |
| a Greek astronomer and mathematician who lived in ancient Egypt and who named many of the constellations |
| | Rigel [RIY-juhl] |
| |
| | Sirius [SIHR-ee-uhs] |
| |
| star | |
| a hot ball of glowing gases; the sun is the star closest to the earth |
This activity is best completed online.
| Are you a sky watcher? Sky watchers like to study the night sky and all the stars. Back in ancient times, sky watchers used their imaginations to see that certain stars form patterns that look like a bear, a hunter, a dog, or other animals, people, and objects. Explore the night sky as you learn about some of the star patterns called constellations. | | |||||||
| Lesson Overview
|
This activity is best completed online.
| Constellations Do you recognize the names Big Dipper or Orion? These are names of some of the many patterns of stars in the sky, called constellations. Explore these constellations and other stars. | |||||||||
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| Do you remember any times you've watched clouds and saw them take the shapes of familiar objects? Clouds sometimes look like animals, people, or other things in nature. Many people see the shapes of familiar objects in star patterns as well. We call these star patterns constellations. Recognizing shapes in the patterns of stars helps us keep track of the stars. | |
|
Answer(s):
[1]
Today's astronomers recognize 88 constellations. You can't see all the constellations at the same time from one place on Earth, though.
| In the year A.D. 150, a Greek scientist named Ptolemy (TAH-luh-mee), living in Egypt published descriptions of 48 constellations that had been recognized for thousands of years. Even though nearly 2,000 years have passed since Ptolemy gazed at the heavens, we can still see those 48 constellations. This tells us that the same stars have been around for a long time, and that they haven't changed much. Actually, many of the stars have been much the same for much longer than 2,000 years. The patterns of the stars, the constellations, stay the same, but they seem to move around in the sky, or across it. The reason is the same as for the rising and setting of the sun and moon. | |
| During the day and night, the sun and moon seem to move through the sky. But it's actually the rotation of the Earth on its axis that makes them appear to rise and set. The rotation of the Earth does the same thing for stars. Many constellations "rise" and "set" like the sun and moon. Others seem to move in a circle in the sky without reaching the horizon -- that's where they would rise and set. Let's find out why this happens. | |
| Do you know the playground ride that spins like a merry-go-round? Imagine lying on that ride, looking up while you spin around. What do you see? The clouds seem to spin above. The one directly above spins in place, while the others circle around it. The farther out you look, the bigger the circle the clouds seem to make around the middle one. That middle cloud is above the ride's axis. | |
| You know that, like the ride, the Earth rotates. In the Northern Hemisphere, Polaris (puh-LAIR-uhs), the North Star, is above the axis. It seems to stay in one place. The other stars seem to go around it. The farther away from the axis a star is, the bigger the circle it makes around Polaris. Stars far enough out make a circle so big that they rise above the horizon and set below it. Only at the North Pole, where Polaris is directly overhead, do all the stars rotate around without rising or setting. | |
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|
Answer(s):
[1]
Just as you couldn't see something under the ride if you were on top, people in the Northern Hemisphere (for example, the United States or Canada) can't see many of the stars that are visible on the other side of the world, the Southern Hemisphere (for example, South Africa or Argentina). And those people in the Southern Hemisphere can't see all the stars of the Northern Hemisphere. The two hemispheres have different constellations in their skies.
[2]
There is no "South Star." No star is over the axis of the Earth in the Southern Hemisphere. However, the other stars still appear to rotate around a point above the axis. There just doesn't happen to be a star there.
| In the Northern Hemisphere, one of the easiest constellations to pick out is Ursa Major. Ursa Major is Latin for Great Bear. Some ancient people saw the shape of a bear in its stars. You probably know part of this constellation as the Big Dipper, so called because it looks like a ladle with a long handle. To find Polaris, the North Star, follow the line of the two stars that form the end of the Big Dipper's scoop, in the direction of the opening of the scoop. Polaris is out about five times the distance between these two stars. Polaris forms the end of the handle of the Little Dipper, which is part of Ursa Minor (the Little Bear). If you could see stars during the day, the North Star would still be there, right in the same place. The rest of the stars seem to revolve around it. Polaris's magnitude is about 2, so there are many brighter stars. | |
|
Answer(s):
[1]
If you're not in the Northern hemisphere, you can get similar instructions for constellations in the Southern hemisphere. Visit the links included in this lesson to recognize constellations in the Southern hemisphere.
| If it's fall, winter, or spring, you can see the constellation Orion (uh-RIY-uhn), the Hunter. In spring you'll need to look earlier after dark, before Orion sets in the west. You can recognize Orion by the three stars that make up his belt, and three less-bright stars that make up the dagger hanging from his belt. His shoulder to your left is the bright star Betelgeuse (BEE-tl-joos), which is much brighter than Polaris. The star at his knee to your right, or at the end of his tunic is Rigel (RIY-juhl)--even brighter than Betelgeuse. To the lower left of the constellation Orion is Canis Major, the Big Dog. Its brightest star is Sirius (SIHR-ee-uhs). Sirius is the brightest star in the sky, although it is much less bright than several of the planets. | |
This activity is best completed online.
| Sky Umbrella How can you turn an umbrella into the night sky? Read on to find out and to see how the constellations seem to move around. Print the Stars of the Night Sky activity sheet if you have not done so already. Follow the activity instructions to complete this activity. |
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Lesson Assessment: Constellations: Star Patterns
This assessment is best completed online, where it will be automatically scored by the computer. If you would like to print it, do so from the assessment itself within the lesson.
This activity is best completed online.
| Twinkling Star If you've ever stared at stars in the night sky, you have probably noticed that they seem to shimmer or twinkle. Learn why they do this by using aluminum foil and some water. Follow the activity instructions to complete this activity. |
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Click "Print Lesson" button to use your browser print Student Name: Alethea
Date Printed: Jan 11, 2015
Science 3
Unit 11: The Solar System and Beyond
Lesson 7: Galaxies
Duration: Approx. 60 min.
There are one or more assessments in this lesson. Offline assessments and answer keys can be printed from the materials lists. Online assessments must be printed from the assessment itself within the lesson.
Firefox cannot print Flash images. The on-screen images might print as blank spaces. If you need to print this lesson, try using Internet Explorer so that all the images print.
For the Adult
*plate, paper - cardboard or card stock
*cotton balls (10)
*glue, children's white
*Galaxies by Seymour Simon
*markers
*scissors
Beyond The Lesson: More About Galaxies
1 day
You will need the book Galaxies by Seymour Simon for the optional activity in this lesson.
Lesson 7: Galaxies
| | elliptical [ih-LIP-tih-kuhl] |
| |
| galaxy | |
| An enormous group of stars, dust, and gas all held together by gravity. The Milky Way is just one of many galaxies in our universe. |
Beyond The Lesson: More About Galaxies
As usual, you may wish to preview any books listed in this lesson.
This activity is best completed online.
| Our solar system contains a star and many planets, as well as meteoroids, asteroids, and comets. But our solar system is itself part of something even bigger--a galaxy. And galaxies are grouped as well. See how scientists have used high-powered telescopes to learn about galaxies--including ours, the Milky Way--and more. | | |||||||
| Lesson Overview
|
This activity is best completed online.
| What Is a Galaxy? Even though its name sounds like something to eat, the Milky Way is a huge group of stars making up the galaxy that we live in. The word galaxy comes from the Greek word for milk. Learn what our galaxy and others look like and how a scientist named Edwin Hubble has classified them. | |||||||||
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| You've learned about stars and their brightness. You know we can use telescopes to see lots of stars and to see them better. You also know that the nearest star other than the sun is very far away. You know that because all the other stars in the sky look very small. Light from the nearest star takes more than 4 years to reach us, compared to 8 minutes from the sun. It seems like the sun is alone in this part of the universe. In a way, it is. But you would not think it was alone if you looked from very far away. That's because you would see many stars around it. | |
| Even though these stars are far away from each other compared to how big they are, they are grouped with many other stars. The stars in a group are much closer to each other than to other groups like them. Such groups of stars are called galaxies. Galaxies can contain many billions of stars! In the picture, so many stars are clumped together in the center of this galaxy that the center looks like one big, bright light. But it contains many individual stars that just do not look separate from this view. | |
|
Answer(s):
[1]
What holds galaxies together? The same thing that holds the solar system together—gravity. Even though the stars are very far apart, gravity attracts them to one another. This is also true of the sun and its planets. Galaxies themselves can even be held together in groups, or clusters. These also form because of gravity.
| Galaxies look different from single stars, especially when we look through a good telescope. The bigger the telescope, the better we can see stars and galaxies. All large telescopes are reflecting telescopes. They use mirrors to gather and focus light. The largest have mirrors 10 meters (32 feet) in diameter. Some of the best views of stars come from the Hubble Space Telescope. Though it has only a 2.4 meter (about 8 feet) mirror, it is outside the Earth's atmosphere, orbiting the planet. The atmosphere can be a problem if you want to see stars clearly. It can affect the light by absorbing, scattering, and bending it. The biggest problem is that changes in the air make images change. Light may dance or twinkle, even though it is coming from one place in the sky, such as from a star. This makes it hard to have a good image that stays in one place. Using good telescopes, including the Hubble telescope, scientists can observe and study galaxies. | |
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|
Answer(s):
[1]
Telescope: "Tele" means "far" and "scope" means "an instrument for seeing." Compare this word to "microscope." "Micro" means "small."
| In 1926, Dr. Edwin P. Hubble classified galaxies as three main types, based on their appearance. These three types are elliptical (ih-LIP-tih-kuhl), spiral, and irregular. The brightest galaxy in the Northern Hemisphere is Andromeda (an-DRAH-muh-duh), a spiral galaxy. Its apparent magnitude is about 3 1/2. Magnitude describes the brightness of galaxies as well as stars. Only in the closest galaxies can we see individual stars. We see more distant galaxies only as shapes. Galaxies are of many sizes. Like stars, galaxies have a life cycle. Some contain many younger stars, as well as gas and dust that has not yet formed into stars. Some have many older stars and not so much gas and dust. | |
|
|
Answer(s):
[1]
Remind your student what magnitude means. Magnitude is a way of classifying stars (and other objects in the sky) by their brightness.
[2]
If you're in the Northern Hemisphere (for example, U.S., Europe, Canada), you can see the bright Andromeda galaxy, just with your eyes. Use a star chart to find it. in the Southern Hemisphere, the brightest galaxies are the Large and Small Magellanic Clouds. They're not really clouds, but look like clouds of stars. These small galaxies revolve around our own Milky Way, so they are called satellite galaxies.
| All the stars you can see are in a galaxy. The single stars are in our own galaxy, the Milky Way. What does the Milky Way look like? Since we live in the Milky Way, we can't see it in the same way we can see other galaxies. Imagine being stuck inside a house, not knowing how it looks on the outside. You can look out and see other houses. You can imagine what they're like inside by what you see on the outside. You can compare them to your house and imagine what it must look like from outside. But unless you leave your house, you can't see it from outside. We cannot leave our own galaxy, and we may never be able to. But we've learned a lot about it from observing it from the inside and comparing our observations to what we see of other galaxies. | |
| The Milky Way is a spiral galaxy. We have a good idea of where we are inside it--about two-thirds of the way from the center to the edge in one of the spiral arms. Scientists have figured this out mainly by counting stars in various directions. You can get an idea of how they did this if you look at a clear night sky, far from city lights. Look up and you will see a band of milkiness across the sky. You are looking through many stars of the Milky Way. When you look straight up, you are looking through the flat disk of the Milky Way, across the wide part of the galaxy. If you look in other directions you see fewer stars because you're looking out the thinner part, closer to the edge. Think of being in the middle of a large crowd of people all blowing bubbles. If you look across the crowd you see lots of bubbles. If you look up, you see fewer. | |
|
Answer(s):
[1]
Scientists recently disocvered that some stars are not party of any galaxy. They used the Hubble Space Telescope to make this discovery. These stars are much too dim to see by eye, though.
| So you live here, on the Earth, in the solar system, in the Milky Way galaxy, about two-thirds of the way out on a spiral arm. Just as the planets revolve around the sun, the entire solar system revolves around the center of the Milky Way galaxy. Scientists calculate that it takes about 240 million years to go around the Milky Way once! It's hard to imagine such long times and the huge distances in our universe. And it's amazing that the force of gravity can hold everything all together. Gravity holds you to the Earth, the Earth around the sun, the sun in its place in the galaxy, and groups of galaxies together over huge distances. But amazing as it is, that is the picture that science has been building. The most exciting thing is, we still have lots to learn! | |
This activity is best completed online.
| Make a Model of the Milky Way Galaxy Can you hold the entire Milky Way galaxy in one hand? After making this neat model, you will be able to! Print the Spiral Pattern activity sheet if you have not done so already. Follow the activity instructions to complete this activity. |
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Lesson Assessment: Galaxies
This assessment is best completed online, where it will be automatically scored by the computer. If you would like to print it, do so from the assessment itself within the lesson.
This activity is best completed online.
SAFETY: As usual, you may wish to preview any books listed in this lesson.
| More About Galaxies Information on the galaxies is as vast as the galaxies themselves. Find out more about the galaxies in the universe by reading Galaxies by Seymour Simon. |
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Click "Print Lesson" button to use your browser print Student Name: Alethea
Date Printed: Jan 11, 2015
Science 3
Unit 11: The Solar System and Beyond
Lesson 8: The Solar System and Beyond: Unit Review and Assessment
Duration: Approx. 60 min.
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| Review what you have learned about the solar system, stars, constellations, the Milky Way galaxy, and other galaxies, as you prepare to take the Unit Assessment. | | |||
| Lesson Overview
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| Planets, Stars, and Galaxies Have you enjoyed exploring outer space? Let's see how much you remember about the sun, planets, stars, and galaxies. | |||||||||
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| Let's see how well you remember what you've learned about space, planets, stars, and galaxies. We’ll start with something close to home--our own solar system. The solar system is the sun and all the things that revolve around it. It includes everything that is related to the sun's region of the universe. Do you know what is at the center of the solar system? Here's a hint: It's the main source of energy on Earth and it contains almost all of the solar system's mass. [1] The planets have most of the rest of the solar system's mass. They have different sizes and are different distances apart. Gravity keeps the planets revolving in their orbits around the sun. Can you name these planets in their usual order, starting from the sun and moving outward? [2] | |
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Answer(s):
[1]
[1] the sun
[2] Moving outward from the sun, the planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
[2] Moving outward from the sun, the planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
| Now it's time to blast off into space and look at things up close. While you're up there in your rocket, look at each part of the solar system starting with the most massive object, the sun. Of course, you mustn't get too close to the sun. You’ll have to study it from a distance. Remember, the temperature at the surface of the sun is 6,000°C (about 11,000°F). Now, that's hot! Look at the picture of the sun onscreen. See if you can name three major layers you learned about. [3] Scientists using a variety of instruments, not looking directly with their eyes, can see the corona during a total solar eclipse. They have many ways of studying the sun's layers. | |
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Answer(s):
[1]
[3] The core (C) is at the center of the sun, the photosphere (B) is at the surface of the sun, and the corona (A) shoots out from it.
| After you leave the sun's neighborhood, the next stop on your journey will be the four planets closest to the sun. Starting with the planet nearest the sun, they are Mercury, Venus, Earth, and Mars. We call them the inner planets because, of the eight planets in the solar system, these are closest to the sun. The inner planets are similar to one another in some ways. They are all terrestrial. Terrestrial means Earth-like, made mainly of rock and metal and having a solid surface. The inner planets are solid, not gaseous. They rotate fairly slowly. They also have no rings and few natural satellites, or moons, or none at all. The inner planets are about the size of the Earth or smaller--less than 13,000 km (about 8,000 miles) in diameter. Look at the picture onscreen and see if you can name each inner planet. [4] | |
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Answer(s):
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[4] A. Mercury B. Venus C. Earth D. Mars
| The next leg of your space journey takes you to the outer planets. Look at the picture onscreen and see if you can name each outer planet. [5] The outer planets are much larger than the inner planets. Which planet is the largest outer planet and also the largest planet in the whole solar system? [6] The next-largest planet is Saturn, which is almost as big as Jupiter, but much less massive. Neptune is the farthest from the sun. Jupiter, Saturn, Uranus, and Neptune are called gas giants. They spin fast and have many natural satellites--moons--of their own. Pluto was once considered a planet, but now it is a "dwarf planet." | |
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Answer(s):
[1]
[5] A. Jupiter B. Saturn C. Uranus D. Neptune
[6] Jupiter
[6] Jupiter
| Notice the patterns of the stars. Some of those patterns will start to change as you leave the solar system. So let's take a look at some familiar ones before we get that far. Many of these patterns have names. Look at the constellations onscreen. They're some of the most familiar constellations in the Northern Hemisphere. Can you name them? [7] Find the two stars that form the end of the scoop of the Big Dipper. Follow the direction in which they point above the dipper, and about five times the distance between these two stars you will see Polaris, the North Star. If you were back on Earth, you would see Polaris directly above the North Pole. It doesn’t seem to move in the sky. It also marks the end of the handle of the Little Dipper, part of Ursa Minor (Little Bear). | |
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Answer(s):
[1]
[7] Big Dipper (constellation on the left) and Little Dipper (constellation on the right)
| As you travel even farther out into space, past all the planets, you can't help noticing all those beautiful stars around you. They're not twinkling, because you're out in space. It's the atmosphere that makes stars twinkle, causing quick changes in their light, including their level of brightness. Think about what else you've learned about the brightness of stars. You've learned that the distance from Earth affects how bright a star looks. But what else affects a star's brightness? If two stars are the same distance away from you, can you think of other reasons one star might look brighter? [8] Do you remember the term that scientists use to describe the brightness of a star? [9] | |
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Answer(s):
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[8] One possibility is that the star that is putting out more light energy looks brighter. The two stars might be the same size, but the brighter one is putting out more energy for its size. Another possibility is that both are putting out similar levels of energy but one is larger and, therefore, puts out more energy overall. Finally, your view of one star might be more obscured by fog or dust or some other material that absorbs or scatters the light. That star will not look as bright as a similar star at a similar distance that has no material to obscure your view of it.
[9] magnitude
[9] magnitude
| Before you head back home in your rocket, get out your telescope and take one more look around. Do you see any galaxies? Galaxies are groups of stars--often many billions of stars. Gravity holds these stars together, just as the sun’s gravity holds our solar system together. How do we know so much about galaxies? We can see them through good telescopes. And the bigger the telescope the better. Telescopes also let us see many faint stars that we could not see with just our eyes. The American astronomer Edwin Hubble identified three types of galaxies by their shape. Look at the three types of galaxies onscreen and name them. [10] Our solar system is part of the Milky Way galaxy. Since we are inside the Milky Way, we see it differently than we see other galaxies. But scientists are always developing new tools for observing things in space, and helping us learn more and more about our solar system and the universe beyond. | |
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Answer(s):
[1]
[10] 1. elliptical 2. spiral 3. irregular
Unit Assessment: The Solar System and Beyond
Print this offline assessment and answer key using the links below. You will need to enter your student's results online later.
Click "Print Lesson" button to use your browser print Student Name: Alethea
Date Printed: Jan 11, 2015
Science 3
Unit 11: The Solar System and Beyond
Lesson 9: Semester Unit Review and Assessment
Duration: Approx. 60 min.
There are one or more assessments in this lesson. Offline assessments and answer keys can be printed from the materials lists. Online assessments must be printed from the assessment itself within the lesson.
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This activity is best completed online.
| From atoms and compounds to the galaxies beyond the Milky Way, you have learned a lot in the second semester. Review these and other units from the second semester as you prepare to take the Semester Assessment. | | |||
| Lesson Overview
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| Semester Review Are you a Semester Whiz? Review the concepts you have learned in the second semester on everything from atoms and molecules to galaxies. | |||||||||
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| Let's begin the Semester Review with a quick look at the solar system and other parts of the universe. The solar system is a collection of eight planets, many moons, and other objects such as asteroids and comets. The sun is at the center of the solar system. But what keeps the solar system together? What keeps the planets revolving around the sun instead of flying off into space? [1] There are billions of stars far beyond our solar system. The stars are much farther away from us than the planets in the solar system are. Scientists classify stars by their brightness, or apparent magnitude. Can you give one or two reasons why some stars look brighter than others? [2] Name a star that you can see almost every day. [3] | |
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Answer(s):
[1]
[1] Gravity keeps the planets in orbit around the sun.
[2] The brightness of a star depends on its light energy output and its distance from Earth, and can depend on whether something is obscuring the view of the star. A brighter star may put out more light energy than a dimmer star, may be closer to Earth, or may have less matter obscuring its light on the way to the observer.
[3] The sun would be the most likely answer. Whether you actually see the sun depends on how clear the sky is.
[2] The brightness of a star depends on its light energy output and its distance from Earth, and can depend on whether something is obscuring the view of the star. A brighter star may put out more light energy than a dimmer star, may be closer to Earth, or may have less matter obscuring its light on the way to the observer.
[3] The sun would be the most likely answer. Whether you actually see the sun depends on how clear the sky is.
| Many stars form patterns in the sky. Can you recall the names of some constellations? One of the most familiar is Ursa Major, which contains the Big Dipper. Since stars are so far away, how can we know much about them? Telescopes magnify the appearance of distant stars, as well as the moon and the planets. By collecting more light than our eyes can collect, telescopes make dim stars more visible. So they help us see more stars than we can see with just our eyes. | |
| Remember the Hubble Space Telescope? This telescope lets astronomers see stars and galaxies far beyond our solar system especially clearly. Galaxies are groups of stars, and may contain many billions of stars. Our solar system is part of a galaxy called the Milky Way. Since we live inside the Milky Way, we can't study it from far away through a telescope in the same way we can other galaxies. | |
| You know that the Earth completes one rotation on its axis every 24 hours, and completes one revolution, or orbit around the sun, in one year. The Earth's tilt on its axis is what causes the seasons. Can you give one reason this tilt causes seasons? [4] The moon also rotates and revolves. The moon makes one revolution around Earth, and one rotation on its axis, in the same time --about one month. Does the moon produce its own light? [5] |
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Answer(s):
[1]
[4] Seasons occur partly because the sun shines more directly on the Earth in the summer and less directly in the winter, and partly because the amount of time the sun shines each day is longer in the summer and shorter in the winter.
[5] The moon does not produce its own light. The moon is visible from Earth because sunlight reflects off its surface.
[5] The moon does not produce its own light. The moon is visible from Earth because sunlight reflects off its surface.
| During a month, the moon's appearance changes. Can you name the order of the moon's phases, beginning with the new moon? [6] For help, look at the pictures onscreen. During a lunar eclipse, the moon can go through similar changes, over hours. That's when the Earth's shadow moves across the moon, keeping sunlight from striking it. On the other hand, when the moon’s shadow blocks sunlight from hitting the Earth, a solar eclipse occurs. |
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Answer(s):
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[6] The order of moon phases is: new moon, crescent, first-quarter, gibbous, full, gibbous, third-quarter, crescent, new moon.
| Click the button onscreen and watch how light moves. Notice how the symbols of photons react as they hit the object. Remember that when light strikes an object it can reflect off the object, pass through it, or be absorbed. But what happens when light moves at an angle from one material to another--for example, from air to water? [7] The color of an object is due to the light that is reflected back to your eyes from it. A green apple looks green, for example, because the apple reflects green light and absorbs other colors of the spectrum. Mainly green light gets reflected back to your eyes. Knowing this, can you recall what type of energy carries the information that sight relies on to form images? Here’s a hint: It’s not heat energy or gravitational energy. [8] | |
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Answer(s):
[1]
[7] Light refracts, or bends, when it passes at an angle through the boundary between air and water or between one material and another.
[8] Sight relies on light energy.
[8] Sight relies on light energy.
| Energy is all around us--inside our houses, outside in forests and fields, and even in the ocean. Energy is everywhere! You know that energy causes changes in structure or motion. Energy is neither created nor destroyed. It is only transferred from one place to another or converted from one form to another form. The lamp in your bedroom takes in one form of energy and converts it to others. Can you describe the conversion of energy in an electric lamp? [9] Look at the picture onscreen and review how plants and animals use energy. The Earth's major source of energy is the sun. Can you picture what the Earth would be like if there were no sun? What a lifeless place it would be! No green rolling hills, no colorful gardens, no thick forests, and no plants and animals. And not only would it be lifeless, it would also be dark and cold! | |
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Answer(s):
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[9] The electrical lamp takes in electrical energy and converts it into light energy and heat energy.
| Both machines and living things convert one form of energy into other forms. Energy can be stored in many objects, such as food, batteries, fuel (gas, coal, wood, and oil, for example), and even stretched rubber bands! Name an object near you that can store energy. [10] Energy resources are either renewable or nonrenewable. Renewable resources include wind, solar energy (from the sun), falling water (for hydroelectric power generation), wood and other plant material, and geothermal energy. Nonrenewable resources include natural gas, oil, coal, and nuclear fission fuel (uranium). Point to each picture onscreen and name the energy source. Tell whether it is a renewable or nonrenewable resource. [11] | |
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Answer(s):
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[10] Answers may vary but may include: batteries (chemical energy, to be converted to electrical energy), an object high up (gravitational energy by separation from the Earth, to be converted to mechanical energy of motion upon falling), gasoline (chemical energy for conversion to mechanical energy and heat energy in a car or lawn mower), wood (chemical energy that can convert to heat energy and light energy upon burning), your body (chemical energy that can convert to mechanical energy in muscles), plants (chemical energy that can convert to chemical energy in an animal upon being eaten), springs (mechanical energy that can be released to mechanical energy of motion).
[11] A. The windmills use wind energy, mechanical energy of moving air, a renewable resource. B. The hydroelectric plant converts mechanical energy in falling water, a renewable resource, to electricity. C. The factory uses oil or coal for the source of energy, both nonrenewable resources.
[11] A. The windmills use wind energy, mechanical energy of moving air, a renewable resource. B. The hydroelectric plant converts mechanical energy in falling water, a renewable resource, to electricity. C. The factory uses oil or coal for the source of energy, both nonrenewable resources.
| Your skeletal system contains all of your bones. It also includes cartilage, tendons, and ligaments. What important jobs do your bones do? [12] Inside bones are tiny passageways that contain nerves, blood vessels, and marrow. Marrow is where blood cells are made. Muscles are another important part of your body. Muscles can only pull or contract. They cannot push bones apart. When you flex your arm and make a muscle, your biceps contracts. Try it. You can move your biceps muscle when you want to. The biceps, therefore, is a voluntary muscle. | |
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Answer(s):
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[12] Bones function for support, movement, protection, and blood-cell formation.
| Look at the picture onscreen and review voluntary and involuntary muscles. What muscles are involuntary--automatically controlled so you cannot move or stop them whenever you want to? [13] Which type of muscle--voluntary or involuntary--lets you bend your knee? [14] | |
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Answer(s):
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[13] The heart muscle and the muscles in the digestive tract, such as in the stomach and intestines, are all involuntary muscles.
[14] voluntary muscle
[14] voluntary muscle
| Now let's look at the skin—your body’s largest organ. Your skin is made up of two main layers—the epidermis and the dermis. Point to the epidermis and the dermis. Check to see if you are correct. The epidermis protects you from germs, as well as minor scrapes, rubs, and bumps. This outermost layer is made up of dead skin cells. These are flat and overlap to form a tough barrier. | |
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Answer(s):
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You can lose millions of skin cells every day. In fact, in a year your body will lose about 2.3 kg--or 5 pounds of dead skin cells.
| Underneath the epidermis, the dermis is springy and elastic. It contains blood vessels, sensory organs, nerves, sweat glands, and oil glands. Even your hair and nails grow from the dermis. The main functions of the skin are to protect the body, regulate temperature, and sense the environment. Do you see how the skin is its own system? | |
| We can classify changes of matter as chemical or physical. A physical change is a change in size or shape, such as slicing a banana, mashing a potato, or breaking a cracker into pieces. A physical change can also be a change in a state of matter, such as boiling, melting, freezing, evaporating, or condensing a substance. Can you give examples of some physical changes in size, shape, or state of matter? [15] We can often tell a chemical change has occurred when we see the temperature rise, light given off, a color change, or the formation of bubbles. We know wood goes through a chemical change when it burns, because it releases heat energy and light energy and changes color. Can you think of other examples of a chemical change? Here’s one--an apple turning brown after you slice it. | |
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Answer(s):
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[15] Answers will vary but may include: ice melting, soup boiling, water evaporating as something dries, water freezing to form snowflakes or ice, a window breaking, a bunch of clay that you form into another shape, a balloon being blown up.
| You learned that matter is made up of atoms. When atoms of different elements come together they form compounds. When the elements hydrogen and oxygen combine, for example, they form water. If you mix the elements sodium and chlorine, they form the compound sodium chloride--ordinary table salt. Click the button onscreen and watch compounds form. All the elements we know are organized in a chart called the Periodic Table of the Elements. Each element is represented in the table by a chemical symbol. The table includes other important information about that element as well. Only elements appear on the table, and not the compounds they form when they combine with one another. | |
| Congratulations! You’ve learned a lot! You have traveled from the tiny universe of atoms and molecules to the giant solar system and beyond, and now back, in this review. You have seen inside the human body and followed the phases of the moon. You’ve studied the colors of the rainbow and the whole spectrum of elements in the periodic table. Consider yourself a Semester Whiz! Good work! | |
Semester Assessment: Science 3, Semester 2
Print this offline assessment and answer key using the links below. You will need to enter your student's results online later.
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